New York Stock Exchange...epa05268814 Traders work on the floor of the New York Stock Exchange (NYSE) at the start of the trading day in New York, New York, USA, 20 April 2016.  EPA/JUSTIN LANE

Justin Lane/EPA

Traders work on the floor of the New York Stock Exchange (NYSE) at the start of the trading day in New York

Scottish Parliament election 2016 campaign ...Audience members hold the SNP party Scottish Parliament election manifesto up during its launch at the Edinburgh International Conference Centre in Edinburgh, as the party bids for its third term in power. PRESS ASSOCIATION Photo. Picture date: Wednesday April 20, 2016. The manifesto pledged to increase NHS funding by £500 million more than inflation over the five-year course of the next parliament, with Ms Sturgeon describing this as "part of a package of investment and reform to equip the NHS for the future". See PA story POLITICS SNP. Photo credit should read: Andrew Milligan/PA Wire

Andrew Milligan/PA

Audience members hold the SNP party Scottish Parliament election manifesto up during its launch at the Edinburgh International Conference Centre in Edinburgh, as the party bids for its third term in power

Government Ministers In Downing Street...LONDON, ENGLAND - APRIL 20:  British Prime Minister David Cameron departs Number 10 Downing Street for the weekly Prime Minister's Question Time (PMQs) session a the Houses Of Commons on April 20, 2016 in London, England. Business continued as normal at Downing Street today ahead of US president Barack Obamas' visit to the United Kingdom.  (Photo by Ben Pruchnie/Getty Images)

Ben Pruchnie/Getty

British Prime Minister David Cameron departs Number 10 Downing Street for the weekly Prime Minister’s Question Time session a the Houses Of Commons in London, England 

TOPSHOT - A Syrian child receives treatm...TOPSHOT - A Syrian child receives treatment at a makeshift hospital following an air strike on a vegetable market in Maaret al-Numan, in Syria's northern province of Idlib, on April 19, 2016. Suspected government air strikes killed at least 44 civilians at two markets in a part of northwestern Syria controlled by the war-torn country's Al-Qaeda affiliate, the Syrian Observatory for Human Rights said. / AFP PHOTO / Mohamed al-BakourMOHAMED AL-BAKOUR/AFP/Getty Images

Mohamed al-Bakour/AFP/Getty

A Syrian child receives treatment at a makeshift hospital following an airInjured in an airstrikestrike on a vegetable market in Maaret al-Numan, in Syria‘s northern province of Idlib

A flock of pigeons take off as a Sri Lankan man makes his way through a street in Colombo, Sri Lanka, Wednesday, April 20, 2016. Some believe feeding pigeons earn them good deeds. (AP Photo/Eranga Jayawardena)

Eranga Jayawardena/AP

A flock of pigeons take off as a Sri Lankan man makes his way through a street in Colombo, Sri Lanka. Some believe feeding pigeons earn them good deeds 

Competitors climb on their way to the "Col De Riedmatten" pass and "Col De Tsena Refien" pass, during the Glacier Patrol race near Arolla, Switzerland, Wednesday, April 20, 2016. The Glacier Patrol (Patrouille des Glaciers), organized by the Swiss Army, will take place from 19 to 23 of April. Highly-experienced hiker-skiers will trek across the Haute Route along the Swiss-Italian border from Zermatt to Verbier. The race covers 53km by foot and ski, which is equivalent to 110km without altitude difference. (Anthony Anex/Keystone via AP)

Anthony Anex/Keystone/AP

This photo taken with slow shutter speed shows competitors climbing on their way to the “Col De Riedmatten” pass and “Col De Tsena Refien” pass, during the Glacier Patrol race near Arolla, Switzerland. The Glacier Patrol, organised by the Swiss Army, started on Tuesday and will continue until Saturday. 

Britain's Prince William is hugged by Chewbacca as British actor John Boyega smiles during a tour of the Star Wars sets at Pinewood studios in Iver Heath, west of London...Britain's Prince William is hugged by Chewbacca as British actor John Boyega smiles during a tour of the Star Wars sets at Pinewood studios in Iver Heath, west of London, Britain on April 19, 2016. Prince William and Prince Harry are touring Pinewood to visit the production workshops and meet the creative teams working behind the scenes on the Star Wars films. REUTERS/Adrian Dennis/Pool

Adrian Dennis/Reuters

Britain’s Prince William is hugged by Chewbacca as British actor John Boyega smiles during a tour of the Star Wars sets at Pinewood studios in Iver Heath, west of London. Prince William and Prince Harry are touring Pinewood to visit the production workshops and meet the creative teams working behind the scenes on the Star Wars films. 

The Wider Image: In search of Don Quixote...The arid central Spanish region of La Mancha is the setting for “Don Quixote”, the seventeenth-century novel by Miguel de Cervantes. Four hundred years after his death, references to the characters of Don Quixote, his loyal squire Sancho Panza and his beautiful lady Dulcinea abound in the surrounding villages from sweet treats to theatre productions involving livestock. Cervantes did not give away the name of the birthplace of Don Quixote, a middle-aged gentleman who becomes obsessed with chivalrous ideals. But many identify the village of Argamasilla de Alba as his hometown. The anniversary of Cervantes’ death is marked on the 23 April. REUTERS/Susana Vera SEARCH "QUIXOTE VERA" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES   TPX IMAGES OF THE DAY  Matching text SPAIN-QUIXOTE/

Susana Vera/Reuters

Windmills at dusk in Campo de Criptana, where Spanish writer Miguel de Cervantes might have drawn inspiration from to narrate the battle between Don Quixote and the windmills he mistook for giants

At least 28 people killed in Kabul suicide attack...epa05266766 An unidentified relative of one of the victims, who was killed in a suicide bomb blast that targeted the Ministry of Defense, reacts after his loved one was killed, in Kabul, Afghanistan, 19 April 2016.  At least 28 people were killed and another 327 wounded in a Taliban suicide attack in a high security zone in Kabul, where an explosion was followed by a clash between Afghan troops and insurgents.  EPA/JAWAD JALALI

Jawad Jalali/EPA

An unidentified relative of one of the victims, who was killed in a suicide bomb blast that targeted the Ministry of Defense, reacts after his loved one was killed, in Kabul, Afghanistan

Expedition 46 On International Space Station...IN SPACE - APRIl 17: (EDITORIAL USE ONLY) (NO SALES) This handout image supplied by the European Space Agency (ESA), shows the Aurora Australis, southern lights, in an image taken by ESA astronaut Tim Peake from the International Space Station on April 17, 2016. ESA astronaut Tim Peake is performing more than 30 scientific experiments and taking part in numerous others from ESA's international partners during his six-month mission, named Principia, after Isaac Newtons ground-breaking Naturalis Principia Mathematica, which describes the principal laws of motion and gravity.  (Photo by Tim Peake / ESA/NASA via Getty Images)

Tim Peake/ESA/NASA/Getty

This handout image supplied by the European Space Agency (ESA), shows the Aurora Australis, southern lights, in an image taken by ESA astronaut Tim Peake from the International Space Station

Spring weather Apr 19th 2016...A ship sits out in the North Sea near Tynemouth beach, North Tyneside, just before sunrise. PRESS ASSOCIATION Photo. Picture date: Tuesday April 19, 2016. Photo credit should read: Owen Humphreys/PA Wire

Owen Humphreys/PA

A ship sits out in the North Sea near Tynemouth beach, North Tyneside, just before sunrise

Tokyo stocks close over three percent on weaker yen...epa05266456 Pedestrians stand before a stock market indicator board in Tokyo, Japan, 19 April 2016. Pushed by the depreciation of the Japanese yen against the US dollar, the Nikkei Stock Average gained 598.49 points, or 3.68 percent, to close at 16,874.44.  EPA/FRANCK ROBICHON

Franck Robichon/EPA

Pedestrians stand before a stock market indicator board in Tokyo, Japan. Pushed by the depreciation of the Japanese yen against the US dollar, the Nikkei Stock Average gained 598.49 points, or 3.68 percent, to close at 16,874.44 

Sumo wrestlers line up as they pray before the start of the annual 'Honozumo' ceremonial sumo tournament dedicated to the Yasukuni Shrine in Tokyo, Japan...Sumo wrestlers line up as they pray before the start of the annual 'Honozumo' ceremonial sumo tournament dedicated to the Yasukuni Shrine in Tokyo, Japan, April 18, 2016.  REUTERS/Yuya Shino SEARCH "SHINO SUMO" TO SEE ALL THE PICTURES.

Yuya Shino/Reuters

Sumo wrestlers line up as they pray before the start of the annual ‘Honozumo’ ceremonial sumo tournament dedicated to the Yasukuni Shrine in Tokyo, Japan

Colombian rescuers work amid the rubble ...Colombian rescuers work amid the rubble in Pedernales, Ecuador on April 18, 2016.  The death toll from the powerful earthquake that struck Ecuador over the weekend has risen to at least 413, government officials reported Monday. / AFP PHOTO / RODRIGO BUENDIARODRIGO BUENDIA/AFP/Getty Images

Rodrigo Buendia/AFP/Getty

Colombian rescuers work amid the rubble in Pedernales, Ecuador. The death toll from the powerful earthquake that struck Ecuador over the weekend has risen to at least 413, government officials reported on Monday

TOPSHOT - A flock of birds fly on the sk...TOPSHOT - A flock of birds fly on the sky of Tbilisi on April 18, 2016. / AFP PHOTO / Vano ShlamovVANO SHLAMOV/AFP/Getty Images

Vano Shlamov/AFP/Getty

A flock of birds fly in the sky in Tbilisi, Georgia 

German Chancellor Angela Merkel (R) and ...German Chancellor Angela Merkel (R) and Indonesian President Joko Widodo inspect a military honor guard on April 18, 2016 before talks at the Chancellery in Berlin.

Tobias Schwarz/AFP

German Chancellor Angela Merkel and Indonesian President Joko Widodo inspect a military honor guard before talks at the Chancellery in Berlin 

The Wider Image: The matador...Spanish matador Jose Maria Manzanares holds his bullfighter's "muleta" during a bullfight at the Real Maestranza bullring in the Andalusian capital of Seville, southern Spain April 9, 2016. At the Real Maestranza arena the crowd enjoys a tradition that dates back over a thousand years. Wearing an embroidered gold and white outfit and wielding a long thin sword, the matador taunts the 600-kilo bull with his cape, dodging its horns again and again. Despite the full stands at the bullring, which hosted its first fight in 1761, the sport attracts an increasingly slim audience, as new generations shun what they see as a cruel and unfair fight. Matadors say those who oppose bullfighting don't understand the bullring's intimacy or the artistry of the fight. To finish off the bout, matadors deliver the "estocada," a deft strike through the bull's shoulder blades to pierce its heart. REUTERS/Marcelo del Pozo   SEARCH "EL MATADOR" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES

Marcelo del Pozo/Reuters

Spanish matador Jose Maria Manzanares holds his bullfighter’s “muleta” during a bullfight at the Real Maestranza bullring in the Andalusian capital of Seville, southern Spain

Hillary Clinton...A Secret Service Agent stands guard as Democratic presidential candidate Hillary Clinton speaks at the Corsi senior center, Friday, April 15, 2016, in New York. (AP Photo/Mary Altaffer)

Mary Altaffer/AP

A Secret Service Agent stands guard as Democratic presidential candidate Hillary Clinton speaks at the Corsi senior center, in New York

Thousands of South African main oppositi...Thousands of South African main opposition party Democratic Alliance supporters march to the Constitutional Court to protest against South African President Jacob Zuma on April 15, 2016 in Johannesburg. / AFP PHOTO / MUJAHID SAFODIENMUJAHID SAFODIEN/AFP/Getty Images

Mujahid Safodien/AFP

Thousands of South African main opposition party Democratic Alliance supporters march to the Constitutional Court to protest against South African President Jacob Zuma in Johannesburg

A high school student holds a candle to pay her respect to the victims of the sunken ferry Sewol during a ceremony on the eve of the second anniversary of the ferry sinking in Ansan, South Korea, Friday, April 15, 2016. Two year ago, as South Korea writhed in grief and fury after more than 300 people, most of them school kids, drowned in a ferry sinking, it seemed things would never be the same.(AP Photo/Ahn Young-joon)

Ahn Young-joon/AP

A high school student holds a candle to pay her respect to the victims of the sunken ferry Sewol during a ceremony on the eve of the second anniversary of the ferry sinking in Ansan, South Korea