What happens when you deselect STP and only have Spars selected?
It would help to see your data here, especially to see how you're calculating the orange line.
Can't seem to attach a data file so here it is:
NC_INIT_DATE ProcessCenterName CurrentYearTarget 1/1/2015 Spars 0.250484 2/1/2015 Spars 0.245154 3/1/2015 Spars 0.239825 4/1/2015 Spars 0.234495 5/1/2015 Spars 0.229166 6/1/2015 Spars 0.223836 7/1/2015 Spars 0.218507 8/1/2015 Spars 0.213178 9/1/2015 Spars 0.207848 10/1/2015 Spars 0.202519 11/1/2015 Spars 0.197189 12/1/2015 Spars 0.19186 1/1/2015 STP 0.093155 2/1/2015 STP 0.091173 3/1/2015 STP 0.089191 4/1/2015 STP 0.087209 5/1/2015 STP 0.085227 6/1/2015 STP 0.083245 7/1/2015 STP 0.081263 8/1/2015 STP 0.079281 9/1/2015 STP 0.077299 10/1/2015 STP 0.075317 11/1/2015 STP 0.073335 12/1/2015 STP 0.071353
As you can see, this data was staged so no aggregation or whatever, to create that sloping straight line (orange color)
The data for the green bars is from a different source and does not have any record for STP in May which is why I have this problem. No data and hence the values for the orange straight line is not plotted for STP in May.
If only Spars is selected then it works fine because Spars has the data (green column) for May.
When both STP and Spars are selected, the dip in the orange straight line is from Tableau not SUMming 0.0852 (for STP in May) with 0.229 (for Spars in May). If it did, then the orange would be straight.
The goal here is for the orange line to be a straight (sloping) line.
Thanks for looking at my post.
Here is what it looks like when only Spars is selected.