How do I change the frequency of Time Machine backups?

I have a Time Capsule and I love that it backs up automatically for me through Time Machine. The problem is, I think hourly backups are too frequent for my needs. It seems as though the computer is always backing up, which slows down the computer. Is there a way to change the frequency of the backups through Time Machine. It doesn't seem to be an option in the Time Machine preferences. Thanks in advance for your help.

 

Thanks