online chess - average time per move

How is average time per move calculated ( how many of most recent online games )  ?    Would like to get an idea how long it'll take to lower mine so I can enter certain tournaments.

I may be badly mistaken on this as I heard this along time ago, like two years ago, but the last I heard it was simply how fast a person moves in all online games in the past 6 months.  the average time per move listing is to make sure that people know that the person that you are about to accept a challenge from, (or in some cases send a challenge) might take three days before moving.  And on the opposite side too.  For those that only have access to internet every three days, they probobly won't accept a G/2 days if the persons average time per move is 20 minutes.  Sadly this can happen as people abuse working hours and work on true work things but then when an opponent has moved in another tab, they go over move and then continue with work.  Obviously this isn't nice to the emplyoers but this can happen.  The average time per move is, in essence, something that tells you how often a person is online.

Thanks. That means if I'd played only 2 or 3 games in the past 6 months, it would be easy to lower it -- the more games one has played, the longer it will take