Traffic light gauge

[#1]

I have a triffic light gauge in a chart. I would like the min value for a segment to be calculated upon the row data.

My expression is this;

=((count(if(INVOICE_DATE>=addmonths(now(), PastMonthQty),INVOICE_REF)))/fabs(PastMonthQty))

However i think it is not just taking the current row into account, but all the selected rows.

How can i get it to only consider the current row?

Steve