Assertion: clay court | /r/ObjectUse | used at wimbledon
Facets:
value: since 1877
type: TEMPORAL
value: historically
type: TEMPORAL
Source sentences:
text: Historically for the Grand Slams grass courts have been used at Wimbledon since 1877, the US Open from 1881 to 1974, and the Australian Open from 1905 to 1987.