Look at the mintage figures for the subway tokens. Remember that there are millions of people in NYC who ride the subway and buses daily. I think that the last number I saw was something like 4.8 million fares per day.
When I first started to work, I'd buy my tokens every payday. So 15 days worth of tokens = a total of 30 and then another 10 or 15 for side trips. The folks that I know who live in the city have taken to buying tokens in rolls. There were 50 in each roll as I recall - autowrapped by the counting machines. So if you have 2 or 3 million people buying these tokens and they need at least 2 per day.
I guess the mintage figures seem very very low.