new Column with a Filter

Hi all , 

I have a date table with mth and Yr i want to create a new column that looks at Mth & Yr only when their is usages 

Thinking something along the line of

Mth & Yr New = VALUES('Date'[Mth & Yr]) & FILTER('Date',[UsagesCount] >= 1 )

UsagesCount = CALCULATE(COUNTROWS('Emporia Device Usage'))

However this does not work. 

Any help would be Appericated

Thanks , James.