Counting team number by month

[HD1080]

Hi,

I'm currently using the attached to work out combined salary per team per month, would it be possible to do count the number of heads per month per team.

the idea will be if the month has no salary in there then that's one less member of the team than there was the previous month. then 2 months later a new salary appears further down the list meaning the teams headcount is back up to what it should be.

thanks,