I have [Report Month] = [1,2,3,4,5,6,7,8,9,10,11,12] & [Report Year] =[2011,2012,2013,2014,2015,2016] fields returned from database
I want to calculate 'Previous Month' based on the [Report Month]
How do I calculate so that the situation of Report Year = 2016 and Report Month = 01(Jan) where now the Previous Month is '12' of 2015