Question: Which of the following was the greatest service returner in the history of the game of tennis: Andre Agassi or Martina Hingis?
Sentence (from "Martina Hingis"): She has spent a total of 209 weeks as the singles No. 1 and has won five Grand Slam singles titles, thirteen Grand Slam women's doubles titles, winning a calendar-year doubles Grand Slam in 1998, and seven Grand Slam mixed doubles titles; for a combined total of twenty-five major titles.
Relevant evidence: No