age of civilizations 2 How do I boost a province economy of 99?

[German Conqueror 9]

I would like to boost a province economy of 99 as it wasn't 99 before, how do I restore the economy of that province?

[princedemchugdongrub 16]

4 minutes ago, German Conqueror said:

I would like to boost a province economy of 99 as it wasn't 99 before, how do I restore the economy of that province?

You first click the province, then click "More" then scroll down to Invest, it will only slightly make the province better, but after repeatedly doing that it'll 'restore the economy' of it