2nd line on chart is a Sum, rather than starting from 0

Hi, I'm creating a simple line chart with 2 lines of data. For some reason, instead of the 2nd line of data starting at 0, it adds on to the first line & therefore overinflates its numbers. (ie. Instead of showing 60% for line 1 and 80% for line 2, it shows 60% for line 1 and 140% for line 2) The entire 2nd line is a sum of the data from the first and 2nd line. Is there a way to get each line to start at 0?? Thanks!!

Thank you! You just solved my problem! I knew it had to be something silly.