I am try to create a line chart with two lines. One is based on the equation Sum(Values) from Apr 2017 to Dec 2018. While the other is Sum(Value * 0.9) from Apr 2017 to Dec 2017. However, the plot is drawing a line past the last data point (Dec 2017) for the second line (circled in red in the screenshot). I've attached a file illustrating my problem.
Screenshot of line chart showing line plotted after last data point for green line.