This doesn't really work. This is assuming you are at your PC, all day, everyday and fill it in at the exact second you can. A more correct calculation would be something like:

Per week: 17 websites * 2 times per hour * 12 hours * 7 days * 0.00000250 = 0.00714
Per month: 0.00714 * 365 / 12 = 0.21717500
For a year I'll take 2 months off. This is including days you're not at your PC, and possible holidays etc.
Per year: 0.21717500 * 10 = 2.17175000 = ~ €200 on a year.

But there are more faucets, so lets say 4 BTC on a years basis for 'working' 12 hours a day.

This only works if you don't have a job, so you're better off getting a regular job and earn 2 - 5 (depends on job, work hours etc.) times  a month, than faucets earn you in a year.