Sweet Spot of an Archer Queen Upgrade level

This is a very interesting graph to show. The question is what level of AQ upgrade give you the best ROI? (Return of Investment). Although we all know each upgrade gives her a bit more HP and a bit more DPS, but how does that translate to destroy defenses.

In this simulation, the person used typical TH10 defenses as benchmark and calculated how many shots would AQ fire to wipe all of them per level. You can see once she hits level 20, her ability of destruction drastically increases. The sweetest upgrades are between level 10 -15 and 20 - 25 where she reduced number of shots by the largest margin. Then it slows down. Once you pass 30, upgrades between 30 - 35 really sux. You are not getting much unless you go all the way to 36. And there is really no point upgrading between 36-40