Growth line for all bars

[Ankur_1]

I have a bar chart showing 24 bars, representing sales for 24 months and I need to represent growth line by comparing the sales of the month to the same month in previous year, for example growth of March 2023 will be calculated based on sales of March 2023 and March 2022. I'm using above function for it : 

(totalsales_SelectedPeriod_MTH - above(totalsales_SelectedPeriod_MTH,12))/above(totalsales_SelectedPeriod_MTH,12)

But it is only showing growth for first 12 bars, while I need for all the bars.