Premise: The list of WTA number 1 ranked players shows the professional women 's tennis players who have been or currently are ranked world No. 1 by the Women 's Tennis Association , along with the dates of first reaching and losing that spot . Maria Sharapova . A United States resident since 1994 , Sharapova has competed on the WTA tour since 2001 . The Women 's Tennis Association ( WTA ) , founded in 1973 by Billie Jean King , is the principal organizing body of women 's professional tennis .
Hypothesis: Maria Sharapova retired from tennis by 2000.
Label: CONTRADICTION