How to make a specific graph

How to make a graph that shows data series as columns or lines, but I want have an additional line that will show the averaged data.

I need something like this or similar:

How to combine the data:

1. all accounts of the medical representative

2. number of meetings (appointment) of the medical representative within the specified period of time

If I add a period of time to the report, there is a change in the number of contractors of a given medical representative. The report does not show all contractors of a given medical representative, but only those appearing in the specified period of time.