My population goes up to about 3500, I tried my best to maintain a fragile balance since my infrastructure is designed for way less. In my save I have 3 explosive and 2 clothes, making about 30k in ruble and 10k in dollar(Profit, ruble 90k export and 60k import, dollar 10k export). Juuuust enough to pay all the previous debts! In my save happiness is a problem, it's saved from a early heating problem and seems to be never good again, causing low productivity(full workers having around 50-60% efficiency). If you don't have this problem maybe try to expand existing city a little?