The data is drawn from the lists at
https://www.behindthename.com/top/
Many of these lists include the number of bearers. If that's the case, then for each name in the top 100 I simply add up the bearers over the year span, and then take the top ten from that.
If the list does not have number of bearers (i.e. it only has the name's rank) then I'll just use the average rank over the year span. This is definitely less accurate but it's the best that can be done.