Colin I base my judgment on the fairness of the system on two things.

1. In theory it is not fair and workable. You stats prove that.

2. I check the positions of a lot of songs not just my own and there are many songs even allowing for fickle public opinion every month that are so far out of position something has to be very far wrong. I have seen songs remain fairly stable for days and then in the space of a few hours move a hundred places or more.