How Often to new maps get released?

Hey,
First of all, I'm a newb( to the site, not RISK itself) and if this seems like a dumb question don't flame me
Anywho, can anybody tell me how often new maps get made/realeased. I was just curious to know...
XenHu
First of all, I'm a newb( to the site, not RISK itself) and if this seems like a dumb question don't flame me

XenHu