People walk past a sign reading "United Russia" on a building in central Stavropol, Russia, September 18, 2016. REUTERS/Eduard Korniyenko

Tennis Britain - Great Britain v Argentina - Davis Cup Semi Final - Emirates Arena, Glasgow, Scotland - 18/9/16. Great Britain's Andy Murray applauds during Dan Evans' match against Argentina's Leonardo Mayer. Action Images via Reuters / Andrew Boyers

Formula One - F1 - Singapore Grand Prix - Marina Bay, Singapore- 18/9/16 Mercedes' Nico Rosberg of Germany leads after the start of the race. REUTERS/Edgar Su

President of the Deutsche Bundesbank Jens Weidmann speaks during a meeting in Rome, Italy April 26, 2016. REUTERS/Tony Gentile/File Photo

A Hanjin Shipping Co ship is seen stranded outside the Port of Long Beach, California, September 8, 2016. REUTERS/Lucy Nicholson/File Photo

A view shows the gold mining town of Diwalwal in Compostela Valley, southern Philippines May 25, 2012. REUTERS/Erik De Castro/File Photo

Small-scale miners and their families sit on sacks containing iron ores mixed in black sand they have gathered at a river in San Marcelino, Zambales, north of Manila February 4, 2013. REUTERS/Erik De Castro/File Photo

A Novartis logo is pictured on its headquarters building in Mumbai April 1, 2013. REUTERS/Vivek Prakash/File Photo