I'm not concerned with active or inactive coins, only how many coins have been generated.
It has no sense. Inactive and dead coins simply doesn't exist for market. You can't predict destruction or inactivation rate in the future, so you can't use fixed emission rate to keep constant coins value. It's something like the nuclear reactor control by using a sledge hammer. One small mistake and... BAAM 
You need adaptive algorithm, which will be based on active coins volume.