Ingots of 99.99 percent pure silver are cast at the Krastsvetmet Krasnoyarsk non-ferrous metals plant in the Siberian city of Krasnoyarsk, Russia, June 5, 2015. Krastsvetmet is one of the world's largest players in the precious metals industry. REUTERS/Ilya Naymushin

A woman looks out of a dusty window after boarding a bus to be transported to see the casket of Nelson Mandela at the Union Buildings in Pretoria, South Africa, Wednesday December 11, 2013. On Thursday, December 5, 2013, Mandela died at the age of 95. (Photo by Markus Schreiber/AP Photo)

In this handout image provided by NASA, the space shuttle Endeavour is seen on launch pad 39a as a storm passes by prior to the rollback of the Rotating Service Structure (RSS) April 28, 2011, at Kennedy Space Center in Cape Canaveral, Florida. During the 14-day mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts, including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Launch is targeted for April 29 at 3:47 p.m. EDT.

The Intel logo is projected on the face of Intel Executive Vice President Dadi Perlmutter as he speaks during a news conference about the 3-D Tri-Gate transistors called “Ivy Bridge” on May 4, 2011 in San Francisco, California. Intel announced a technical breakthrough in the microprocessors with the world's first Tri-Gate transistors, that will increase speed and consume less energy. (Photo by Justin Sullivan/Getty Images)

Camels walk down a street at the end of the Three Kings Day Parade in East Harlem on January 6, 2012 in New York City. (Photo by Mario Tama/Getty Images)

Poland's Piotr Lisek celebrates after winning in the Men's pole vault during the IAAF Diamond League competition on July 12, 2019 in Monaco. (Photo by Eric Gaillard/Reuters)

A girl yawns as she and others wait for the start of their first day in school, an occasion known as the Day of Knowledge, in the small town Ignalina, some 110km (68 miles) north of the capital Vilnius, Lithuania, Monday, September 2, 2019. (Photo by Mindaugas Kulbis/AP Photo)

Carla Bruni attends the L' Oreal Party at the Beach of The Palais du Festival during the 51st Cannes Film Festival on May 13,1998 in Cannes, France. (Photo by Foc Kan/WireImage)