Caroline Wozniacki is a Danish professional tennis player. She is a former World No. 1 on the WTA Tour. As of 23 January 2012, she held this position for 67 weeks. She was the first Scandinavian woman to hold the top ranking position and 20th overall. From her WTA debut in 2005, she improved her year-end ranking each year until finishing on top in both 2010 and 2011. Wozniacki has won 21 WTA singles titles as of October 2013, three in 2008, three in 2009, six in 2010, six in 2011, two in 2012 and one in 2013. She was runner-up at the 2009 US Open and the 2010 WTA Tour Championships in Doha to Kim Clijsters. She won the 2006 Wimbledon Girls' Singles title but has yet to win a women's Grand Slam title. She also holds two WTA titles in doubles.