Save files have the following format:

Offset 0x0000 : History of residential levels (240 16-bit integers)
       0x01E0 : History of commericial levels
       0x03C0 : History of industrial levels
       0x05A0 : History of crime levels
       0x0780 : History of pollution levels
       0x0960 : History of cash flow
       0x0B40 : Miscellaneous values
       0x0C30 : Map data (by columns, west to east)
