odd description in customizing opponent screen

I have some doubts about the description of the "financial ressources" settings in the customizing opponent screen:

When you see the value +100% and a description saying "this values determines how much the additionnal taxes the AI collects in comparaison to the player"; you naturally understood that 100% is the bonus and not that the AI collects the same level of taxes than you.

The "additionnal" word is pretty misleading here.