How often do you clean your contacts database?

I routinely audit and clean my contact database, to try and keep everything up to date and in order. I go through my files and see who is still a client/customer with me still, if they aren’t still with me then I move them out. It really isn’t that hard or time consuming if you keep up on it. Usually I routinely do it, if not at least every 3 - 6 months I will do it.