Let's say there is a six-way tie for 13th place one week, at four listeners. Since the next tier would start at 19th place, those 6 artists are the bottom tier and get one point apiece. Those with five listeners would get 2 points, and those with ten listeners would get 7 points. If the bottom tier is at three listeners the following week, that tier would get 1 point and ten listeners would be worth 8 points.
The monthly score is just the sum of the weekly scores. (Note that even though an artist who gets points one week may have one or more listeners in another week, those won't count unless the rank is 15 or higher.)
Two more lists are produced, one for albums and one for tracks, following similar rules, with one difference: