Create a MoM % sales change KPI

[drulj2]

Hi! I am trying to have a % change month over month kpi indicator for sales, based on the selection of a date.

I am thinking on using set analysis for this, to grab the max of current month minus max of current month -1.

However I would lik to know if any of you have a simple way to calculate MoM %

Any help would be appreciated!