Gold medallist Rachelle Simpson of the U.S. celebrates after the women's 20m high dive competition during the Aquatics World Championships in Kazan, Russia August 4, 2015. (Photo by Hannibal Hanschke/Reuters)

The Screamin' Sasquatch jet powered Waco Biplane sits on display during media day for the Canadian International Air Show at Billy Bishop Airport, Toronto, Ontario, September 4, 2015. (Photo by Louis Nastro/Reuters)

A boy dressed like Hindu Lord Krishna waits to attend celebrations on the eve of Janmashtami at a school in Mumbai, India, Friday, September 4, 2015. The day marks the birth of Krishna. (Photo by Rajanish Kakade/AP Photo)

A woman lies face-down on the floor where other race-goers are standing on 2017 Derby Day at Flemington Racecourse on November 4, 2017 in Melbourne, Australia. (Photo by Splash News and Pictures)

A racegoers cheers on her horse in Race 4 ahead of the race of the Melbourne Cup at Flemington Racecourse in Melbourne, Australia, Tuesday, November 7, 2017. (Photo by Andy Brownbill/AP Photo)

A coach wipes away tears and comforts a girl who was feeling tired during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, May 4, 2016. (Photo by Aly Song/Reuters)

Cheerleaders let their hair fly as they perform prior to a German first division Bundesliga soccer match between 1. FC Cologne and Bayern Munich in Cologne, Germany, March 4, 2017. (Photo by Michael Probst/AP Photo)

Singer Katy Perry arrives at the Metropolitan Museum of Art Costume Institute Gala 2015 celebrating the opening of “China: Through the Looking Glass” in Manhattan, New York May 4, 2015. (Photo by Lucas Jackson/Reuters)