How much Ritalin can I take?


I am 41 years old and comes from Norway..I have been using ritalin for about 4-5 months. I have used 20mg 3 times a day quite sometime but know I have started to use 25 mg 3 times a day by my own choice..I have read that 60mg is the maximum dose. I wounder if 75mg ritalin is dangoures since the maximum dose now are 15mg more?

I would also like to say hello to everybody on this forum:-)