I have an important question regarding the count of one of my themes

I have top 5 theme for a long time now. I noticed today the the count was way lower then normal and so I downloaded the theme to see if there was a problem. Anyways it got me to thinking and can someone explain exactly the way the count works??? I have been here far too long not to know exactly how things work. One reason I ask is I never see it zero out so I am curious. I see my count is different as on last page when updating the theme then it is on count on the actual page for the theme. To be honest I think the count is messed up on my theme. Why else would it show different in two different locations and it is highly unlikely it dropped that much after keeping the same average for 3 months. I just wish someone would help me with this. I know the count may get fixed at the end of the month but that does not help me with my download rankings at all. I may be wrong but I am not wrong about count showing different in two different locations. Any help would be greatly appreciated.