I think certain development milestones are locked behind events - depending on what route you go, particularly with the salarymen, I believe it's simply not possible to peak over a certain number. At least, last I tried with the office route, the highest I could get was 199.
Not sure what to tell you if you're on the train, but otherwise it might be a matter of whatever event necessary for peaking over 100 simply not being in the game yet.
Not sure what to tell you if you're on the train, but otherwise it might be a matter of whatever event necessary for peaking over 100 simply not being in the game yet.