Following an outstanding junior, college, and amateur career, Woods was 20 years old when he turned professional at the end of summer in 1996. By the end of April 1997, he had won three PGA Tour events in addition to his first major, the 1997 Masters. Woods won this tournament by 12 strokes in a record-breaking performance and earned $486,000. He first reached the number one position in the world rankings in June 1997, less than a year after turning pro. Throughout the 2000s, Woods was the dominant force in golf—he won the 2000 U. S. Open by a record 15-shot margin. He was the top-ranked golfer in the world from August 1999 to September 2004 (264 weeks) and again from June 2005 to October 2010 (281 weeks).