Using master dimension to count the numbers

[zhj0735]

I have a question about the expression using the master dimension of YRMON to make a table that counts the VINs if the sold_date <= YRMON:

=count(if(sold_date.autoCalendar.Year&num([sold_date.autoCalendar.Month],'00')='<=$(YRMON)',[vin]))

However, the counts are always zero even though the expression check is "OK". Wondering any body have any idea how to write the right expression?

I think it might caused by the master dimension I created YRMON, which might not read correctly by the Qlik Sense.

I have self-educated myself from scratch with numerous classes but still struggling with this simple request. Thanks in advance

[zhj0735]

One thing I am not sure about is that using the master dimension in the expression. I can see the expression read in  actually omit the master dimension (YRMON) I created.