Don't get me wrong getting and staying at number 1 for a long period of time is an important achievement - but time there doesn't always reflect what is actually happening completely in a career.
Case in point...if Djokovic continues to hold number 1 until the end of the year - that means he will exceed Nadal in number of weeks and no. of year ends as number 1, even though he has won only 1/2 the slams (if he doesn't win the US open this year). Even if he doesn't end the year at number 1, in 12 weeks time (at the time of writing he is currently on 91 weeks and Nadal's total is 102 weeks) he has a decent chance of exceeding Nadal's total. Hence, only 1/2 the slams but longer at number 1.
Again, time at number 1 is important to your career CV - however time there doesn't reflect exactly what was going on in your career in terms of Slam wins.
(Having said this I think that Nadal is likely to get back to number 1, even later this year).
Case in point...if Djokovic continues to hold number 1 until the end of the year - that means he will exceed Nadal in number of weeks and no. of year ends as number 1, even though he has won only 1/2 the slams (if he doesn't win the US open this year). Even if he doesn't end the year at number 1, in 12 weeks time (at the time of writing he is currently on 91 weeks and Nadal's total is 102 weeks) he has a decent chance of exceeding Nadal's total. Hence, only 1/2 the slams but longer at number 1.
Again, time at number 1 is important to your career CV - however time there doesn't reflect exactly what was going on in your career in terms of Slam wins.
(Having said this I think that Nadal is likely to get back to number 1, even later this year).