I need to create a rolling 12-month chart that shows the distinct counts for the previous specific 12 months (i.e. not a cumulative amount from month to month, but a distinct count for each of the previous 12 months).

I am looking at denial dates (event) for each month going back 12 months. I want to chart both the sume of denied cases as well as the sum of denied amounts (one can be a bar and the other can be a line superimposed). I have checked a lot of sites online and have come away more confused than enlightened.

Thanks, in advance!