Elderly people attend an aquatic exercise at a private pool in Bangkok, Thailand, April 28, 2016. Many Thai families look after elderly relatives at a cost that countrywide adds up to just under a third of household income. The number of families facing this issue will balloon as the population ages at a rate among the fastest in Southeast Asia. (Photo by Athit Perawongmetha/Reuters)

A pile of destroyed cars of teachers sits outside Briarwood elementary school in Oklahoma City, Oklahoma May 22, 2013. Rescue workers with sniffer dogs picked through the ruins on Wednesday to ensure no survivors remained buried after a deadly tornado left thousands homeless and trying to salvage what was left of their belongings. Curvature of horizon in the photo is due to an ultra-wide angle lens. (Photo by Rick Wilking/Reuters)

A New York window cleaner strapped to the side of The RCA Building in the Rockefeller Center, with St Patrick's Cathedral below him to the left. (Photo by William Lovelace/Express/Getty Images). 2nd May 1961

Farmers plant rice seedlings in a paddy in Karanganyar, near Solo, Central Java, Indonesia in this April 13, 2016 photo taken by Antara Foto. (Photo by Maulana Surya/Reuters/Antara Foto)

People use a board to travel on a flooded street after heavy rainfall in Baghdad, Iraq, October 31 2015. (Photo by Ahmed Saad/Reuters)

Sunday night, Lauren Watts searches for her dog in Mayflower, Arkansas., after a tornado struck the town. (Photo by Benjamin Krain/The Arkansas Democrat-Gazette)

Ultra-Orthodox Jews inspect etrogs, or citrons, inside a shop in the Mea Shearim neighbourhood in Jerusalem, 07 October 2014, as they look to purchase an unblemished fruit ahead of the holiday of Sukkot. (Photo by Jim Hollander/EPA)