Mutation rate changing

[Finger]

Hello!

I have some question about changing of the mutation rate during GA proccess.
In a simple GA with a high  genome length and a not so large population size
the mutation rate must to be near to 100% at the begin of the proccess and
as small as a zero at the end, otherwise the procces will be too long and
pearhaps will don't find the optimal solution. Where I can find some kind of
algorithm of current mutation rate calculating? I guess it will depend on
the population properties such as fitness variety.

With best regards, Finger.