My server got average: "5" and dont move i got on my server daily minim 10 players and 3 hours per day 19/24, but still average dont move.
How is the system of average?

If this is the server http://www.gametracker.com/server_info/92.55.137.103:27015/

The average is the average number of players across every scan. If you have 10 players for only 3 hours per day, your average would be less than 5. Please visit http://en.wikipedia.org/wiki/Average#Arithmetic_mean to learn what a mean is.

If you have 10 players half the day and 0 players for half the day, your average would be 5. The calculation is very simple and does not just contain information about when players were in the server, as that would be incredibly inaccurate as to how popular the server is.