Political Chart

Hey Anonymous, let me know if this is closer to what you're after. I'm not completely familiar with the dataset, but it appears a key difference between your dataset and PBI-David's is that he has a row for each dot, where your table is aggregated. That's why there were only 21 dots. I'm also not sure what the relationship between seats and mandates is, so if the label should say "Total Mandates", that's an easy fix.

In Deneb I exploded your dataset using the sequence and fold transforms. 

If you expect a different color scheme, let me know which parties should be associated to which colors.

.pbix: https://github.com/Giammaria/PublicFiles/blob/master/PBI%20Community%20Help/Parliament%20Seat%20Projections.pbix

Anonymous, I enjoyed making these updates. Hopefully this is closer to what you're after. Let me know.

Note - I had to create a disconnected party table for the slicer and a measure to detect when opacity should change.

.pbix: https://github.com/Giammaria/PublicFiles/blob/master/PBI%20Community%20Help/Parliament%20Seat%20Projections.pbix