Display KPI Light Last Month Status in Report Table

Hi v-jiascu-msft

Thank you for your support!

If I reduce the formula to show Year & Month - 1,  I will lose the visibility of those supplier sites whose last update are before June. Please see my screeshot below, the supplier site "Hanau" as an example. 

Only 4 suppliers shown (Hanau is missing)

Previous screenshot I'm think to add another condition to my last formula:

LastMonth =

IF(

        YEAR(TODAY ( ) ) = YEAR ( 'SM KPIs' [Month-Year]) && MONTH ( TODAY ( ) ) -1

                   = MONTH ( 'SM KPIs' [Month-Year] );

        1;

         IF (

                   YEAR( TODAY ( ) ) = YEAR ( 'SM KPIs' [Month-Year] ) && MONTH ( TODAY ( ) ) -2

                               = MONTH ( 'SM KPIs' [Month-Year] );

                   1;

                   IF (

                          YEAR(TODAY ( ) ) = YEAR ( 'SM KPIs' [Month-Year] ) && MONTH( TODAY ( ) ) -3

                                       = MONTH( 'SM KPIs' [Month-Year] );

                          1;

                          BLANK ( ) ) ) )

My thought is to add an additonal formula.. 

for each supplier, sumlastmonth = sum ( 'last month' )

If sumlastmonth = 3, return Year & Month -1,

If sumlastmonth =  2, return Year & Month -2,

If sumlastmonth = 1, return Year & Month -3, else blank

The problem of this formula is that if the last update of the supplier site is before April, no KPI light will be displayed.

Can you please advise on it? Thank you!!

Kind regards,

Jaz