Prevent Line Chart Made from Pivot Table to Fall to Zero

Hi guys. Does anyone know how to prevent a line chart built from a pivot table to fall down to zero which makes the cart showing as if the performance dropped really bad? Understand that maybe one of the solutions is to make the chart not from a pivot table, but I cannot do that since I need to be able to filter the chart using other dimensions/fields in data (in my sample is the "Subscription" field, but in my real case I have more than one dimensions/filters need to be present in the chart) which as far as I understand cannot be done on a line chart made not from a pivot table. Have tried to change the zero performance records to #N/A but since I need to make the line chart from a pivot table, it just made the line stops at an earlier x-axis (to be precise, at the point where all fields are not having #N/A values). Have also searched on the internet for a solution but seems solutions that I found so far are only for the line chart not made from a pivot table. Here I also attach the Excel file for a clearer understanding of my question. Hope anyone can answer. Thanks!