I think you mean # of years ending as at #1?
No, I meant total weeks at #1. I don't think that it really matters too much who's number one at the end of the year. That's just a random time of the year to do the numbers - might as well have chosen august 16th to do those numbers and it would turn out differently. For instance, on the WTA tour Hingis have spend far more weeks at #1 than Davenport, but Davenport have ended the year as #1 more times than Hingis. Total weeks at #1 is the best measure of dominance here.