Here is a graph of the ATP points for the top 8 tennis players in the world since 2009.  It’s interesting to note that since 2009, Andy Murray has been ranked above each of Nadal, Djokovic, and Federer at some point, but never above them all at once.  Also, over that same time period n0one of the players currently ranked 5-8 have ever been ranked higher than any of the top 4 players.

Cheers.