Um, I've never paid any attention to the Asset Index. I'm not sure it's important. For Finance Index (FI), I doubt you'll be wanting to go below 100 since that would mean you're losing money. The max FI you can get while your country costs are below 100M monthly is somewhere between 150 and 160. When your costs exceed 100M monthly, your FI becomes unbounded I think (or at least is able to surpass 160 FI).
Anyway, back to my first point, FI below 100 means you're losing money so that would be the floor and everything above that would bring benefit (profit) to the country.