Ko has played only 22 events to reach that level, 20 less than world No 6 Karrie Webb and 40 less than No 1 Inbee Park.
Her win at 16 years, four months and one day old made her both the youngest and second youngest winner in LPGA Tour history. She won the event last year at 15 years, four months and two days old.
Ko is yet to miss a cut in 24 professional events, she has finished as the low amateur in majors on five occasions and has recorded six top five finishes this year.
Ko's next tournament is the Evian Championship in Evians-les-Bains, France, starting September 12 - a major-rated tournament for the first time - where she will look to make further history and become the youngest major champion in golf.
The world top 10: Inbee Park (Korea) 64 tournaments, 12.78 points average 1, Stacey Lewis (US) 54, 9.43 2, Suzann Pettersen (Norway) 50, 8.15 3, Na Yeon Choi (Korea) 55, 7.67 4, So Yeon Ryu (Korea) 54, 7.05 5, Karrie Webb (Australia) 42, 6.12 6, Lydia Ko (NZ) 22, 5.85, 7, I.K. Kim (Korea) 47, 5.77 8, Shanshan Feng (China) 61, 5.77 9, Catriona Matthew (Scotland) 44, 5.58 10.
* Note: Ko has played two tournaments which are not included in the world ranking list.