What is the average percentage of a taxi driver's fares and tips that are paid out to rent/lease the cab?

I was just talking about this with a cab driver last week--he says it's different in every city. In San Francisco where I live he said he pays about the first $100 to leasing the cab, and then spends about $25 per day on gas, and the rest he can pocket. There are big differences in how much you can make depending on the city and whether you have the daytime/night shift.

Also, this may be more info than you are looking for, but another big factor is what kind of car you drive and how much fuel it needs. Most cabs are Crown Victorias and they get low MPG, but some cities are introducing hybrid cabs which means the driver spends less $$ on fuel. In NYC the whole situation is more expensive because it can cost literally hundreds of thousands of dollars to get a yellow cab medallion, and fuel is more expensive because there are 13,000 cabs in NYC and so far only a tiny handful are hybrids (the taxi fleets sell fuel to their drivers, so since they profit off of gas-sucking cars, they have been fighting behind the scenes to stop the city from allowing more hybrids).

Thanks for the response. . . Is that the first $100 daily, weekly, or monthly that is paid out to lease the cab? I'm really asking this question because I am working for a bike taxi company which charges $20-$25 for the driver to use the bike for a 4 hour shift. I live and work in Chapel Hill, North Carolina, and tend to bring in $65 to $90 a night before I subtract out the $25. The bikes themselves cost $900 and there is moderately cheap maintenance that needs to be done on them. The job is a great work out, besides getting me a little extra cash, but I want to know if paying 25-35% of fares and tips is common/fair for a cab driver (especially given that the cabs are a much cheaper investment than a traditional taxi.