For how many weeks has the athlete who defended her title in the 2007 Acura Classic-Singles been ranked world No 1 by the WTA?
2007 Acura Classic – Singles: Maria Sharapova successfully defended her title, by defeating Patty Schnyder in the final. Maria Sharapova:  She has been ranked world No. 1 in singles by the WTA on five separate occasions, for a total of 21 weeks.
21