Variance from Historical Average
I'm looking to create a card that shows the percent and/or change in a value for last month compared to the last 12 month average. So if last month there was $1M in revenue but the last 12 months averaged $1.2M per month in revenue, I want to show -16.7%. This would be very similar to the "Compare" functionality on period-over-period charts, however that's limited to the last 1-4 months specifically or the same time last year.
My intent is to ultimately establish thresholds for conditional formats and alerts to more proactively notify department owners of these variances so I'm open to suggestions if if there's also a different way to accomplish the same goal.