That won't work even if you get those numbers from file and use them there, because settings are loaded only one time on plugin_init and at that time amount players connected to server equals 0.
Trying to load settings before each voting won't work either, because function that is supposed to clear array is somehow screwed (or at least it didn't work for me and voting after map extending was bugged because of it).
I'm right now working on exactly same thing and I have already rewritten most of the code and added more features.