Rule for vertical line
I have horizontal bar graph that represents completion rate of expanse categories For each month we have a benchmark set up, for example if I select Jan-16 we should be utilizing 1/12 = 8% of our overall budget, for Feb, 2/12 = 17% of overall budget. To see where our expanse category stands against benchmark for each month I need to draw a vertical line which changes as we change the month. In my data table I have separate "columns" for Month and this expanse categories.
Attached is the example, I have fixed the line at 50% since we are looking for June, how can I move this line as I change the months? How can I add a rule to achieve this task? Can somebody suggest me the expression for it?
Thanks so much for your time.