A 20 metre high spiral staircase in a tower used as an emergency exit, is seen inside a Federal Reserve bank (Bundesbank) bunker, prior to the bunker's official opening to the public in Cochem, Germany, March 18, 2016. West Germany's Central Bank (Deutsche Bundesbank) stored some 20 billion German marks of emergency notes in two underground bunkers, one in Frankfurt the other in Cochem, between 1964-1988 during the cold war. (Photo by Kai Pfaffenbach/Reuters)

Women are covered in dust after making it out of a building that collapsed after an earthquake in the Roma neighborhood of Mexico City, Tuesday, September 19, 2017. A powerful earthquake shook Mexico City on Tuesday, causing panic among the megalopolis' 20 million inhabitants on the 32nd anniversary of a devastating 1985 quake. The US Geological Survey put the quake's magnitude at 7.1 while Mexico's Seismological Institute said it measured 6.8 on its scale. The institute said the quake's epicenter was seven kilometers west of Chiautla de Tapia, in the neighboring state of Puebla. (Photo by Rebecca Blackwell/AP Photo)

Crowds supporting the Same Sеx Marriage Survey listen to politicians and advocates at Taylor Square in the heart of Sydney's gay precinct on November 15, 2017 in Sydney, Australia. Australians have voted for marriage laws to be changed to allow same-sеx marriage, with the Yes vote claiming 61.6% to to 38.4% for No vote. Despite the Yes victory, the outcome of Australian Marriage Law Postal Survey is not binding, and the process to change current laws will move to the Australian Parliament in Canberra. (Photo by James Alcock/Getty Images)

A SpaceX Falcon Heavy rocket lifts off from historic launch pad 39-A at the Kennedy Space Center in Cape Canaveral, Florida, February 6, 2018. The world' s most powerful rocket, SpaceX' s Falcon Heavy, blasted off Tuesday on its highly anticipated maiden test flight, carrying CEO Elon Musk' s cherry red Tesla roadster to an orbit near Mars. Screams and cheers erupted at Cape Canaveral, Florida as the massive rocket fired its 27 engines and rumbled into the blue sky over the same NASA launchpad that served as a base for the US missions to Moon four decades ago. (Photo by Thom Baur/Reuters)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Employees stand near an airframe for the second Antonov-225 Mriya plane at Antonov aircraft plant in Kiev, Ukraine, September 7, 2016. Ukraine hopes to attract $500 million of investment from China to complete an updated version of the world's biggest aircraft, the Antonov-225 Mriya, the president of manufacturer Antonov said on Wednesday. (Photo by Valentyn Ogirenko/Reuters)

A festival goer uses a hula hoop, as revelers gather ahead of this weekends Glastonbury Festival of Music and Performing Arts on Worthy Farm in Somerset, southwest England, on June 25, 2014. US metal giants Metallica will play this year's coveted Saturday night headline spot at Britain's Glastonbury festival, organisers announced Thursday. It will be the “Master of Puppets” four-piece's first appearance at the legendary festival, held in south west England, following on from The Rolling Stones' Worthy Farm debut last year. (Photo by Leon Neal/AFP Photo)

Children clean the interior of a granary in preparation for grain storage in Odek village, north of Uganda capital Kampala February 14, 2015. Odek is the birthplace of Joseph Kony, founder and leader of the rebel group Lord's Resistance Army. The LRA rose up against the government in northern Uganda under the leadership of Kony in the late 1980s and has been accused of abducting children to serve as fighters and s*x slaves. (Photo by James Akena/Reuters)