Show interval points on scatter plot

This question is going to require you to look at the actual file I am looking at. However, the file is very large, so I am attaching a condensed version of it for the sake of allowing you all being able to view it.

I am building a tool that compares two data series. I have the data laid out the way I want it, and the chart built. However, now I want to incorporate something new into this chart. In cells D3:F6, there is a table showing 4 different intervals, 20/40/60/80 %. There is then a VLOOKUP attached to two different pivot tables, showing the point at which these thresholds are crossed in terms of the rolling total of dollar sales.

I have built a scatter plot attached to these rolling sales numbers. What I need is a way to add points to each of these lines showing the number of products at which each threshold is crossed. So when the first line crosses 20% on the X axis, have a point on the line with (in this case) the number 3 attached to it, signifying that it takes 3 products to generate 20% of the dollar sales.

In the original file this is all pivot data, and there are five different filters on each pivot table, so it cannot be a static solution. It needs to be attached to the pivot data, so that it will change when the table is changed.

I hope that this makes sense, please comment if it needs to be clarified. And I really hope that someone can help me out. Thanks!