LONDON, ENGLAND - JULY 12: A 'Keep Off The Grass' sign is pictured on Centre Court on day 13 of the Wimbledon Lawn Tennis Championships at the All England Lawn Tennis and Croquet Club on July 12, 2015 in London, England. The 129th tournament to be hosted at Wimbledon is due to run for two weeks from Monday 29th June.  (Photo by Carl Court/Getty Images)