It's definitely quite a bit of time, but I can break about 150k an hour when I'm paying attention so it's not all that much, comparatively.

Btw, I just looked something up. From now to lvl-99 (1,228,813 experience) I'll only advance 86 ranks on the highscores (I'm not even kidding). BUT! After hitting lvl-99, if I advance JUST another 25,000 experience, I'll gain over
200 ranks (one rank per every 125 experience average), and I'll be on the top thousand!