Paul, I didn't address that part, Aussiebear made that a separate thread http://www.vbaexpress.com/forum/show...selected-range
So the only thing which changes on the chart is the added Opportunities series.
I'm guessing you mean that you don't use it, because if the formula works at your end I feel you must have Power Query (Get & Transform Data on the Data tab of the ribbon). The query tables need refreshing in the same way as you would refresh Pivot Tables (after changing the value in cell G37, either right-click each (green) table and choose Refresh, or click Refresh All in the ribbon).
As far as 'is there another way?', well, yes, the formulae in cells J36:K36 (and R36), unless I've misunderstood.