Growth rates (Month Over Month) formula

[dmitrpav]

Hello all,

I want to make growth rates for Revenue Month over Month ( = percent change) for this table:

 

The problem is that every date occurs 28 times, sice there are 14 countires and 2 sources. 

So, I need to sum up values for all dates taking into account country and source, the sum up all values for all dates in the month, and finally calculate the percentage change.

Here is the formula that I tried to use, but it doesn't work properly.

Revenue % Change = 
VAR RevenueLastMonth =
    CALCULATE (
        SUM ( Tables[Revenue] );
        FILTER(Tables;
            Tables[Month]
                = ( EARLIER ( Tables[Month] ) - 1 )
                && Tables[Country] = EARLIER ( Tables[Country] )
                && Tables[Source] = EARLIER ( Tables[Source] )
        )
    )
RETURN
    IF (
        ISBLANK ( RevenueLastMonth );
        0;
        ( Tables[Revenue] - RevenueLastMonth )
            / RevenueLastMonth
    )

I will be very grateful for your help!