According to Josh Meiseles of ATP World Tour, Novak Djokovic has clinched a very unique and difficult-to-achieve milestone. The World No. 1 and ten-time major champion will remain at the top of the ATP Rankings table for the rest of the season, ensuring that he will become the sixth player in history to ever hold the No. 1 ranking for all 52 weeks of a year.

Read the full article at ATPWorldTour.com here

Roger Federer (2007) is the last player to achieve the feat.

Here is a complete breakdown, via ATP World Tour, of the other times the milestone has been achieved:

2015, Djokovic
2007, Federer
2006, Federer
2005, Federer
2002, Hewitt
1997, Sampras
1994, Sampras
1987, Lendl
1986, Lendl
1978, Connors
1976, Connors
1975, Connors

Djokovic has clinched the year-end No. 1 ranking for the fourth time in his career. The Serb becomes the sixth ATP player to own four or more year-end No. 1 finishes, joining Sampras (6), Connors, Federer (5) and Lendl, McEnroe (4).