Politician Archive

Please don't yell at me if I've missed this somewhere, but I'm a noob soon-to-be-mayor and can't seem to find a list of (a) which structures are available at which city levels (beyond the shuttleport at level 4), and (b) what population you need for each city level. I've looked through the FAQ and the online help in the game, but can't find these statistics.

Thanks very much!