Calendar Pivot with sum total of different expression

[mellerbeck]

Given 

[Category]:
LOAD * INLINE [
Category, Model
CatA, Model1
];

[Data]:
LOAD * INLINE [
Model, MonthNum, Margin, Volume
Model1, 1, .10, 100
Model1, 2, .10, 100
Model1, 3, .10, 100
Model1, 4, .10, 100
Model1, 5, .10, 100
Model1, 6, .20, 100
Model1, 7, .20, 100
Model1, 8, .20, 100
Model1, 9, .20, 100
Model1, 10, .20, 100
Model1, 11, .20, 100
Model1, 12, .20, 100
];

I create a pivot calendar table.

What I would like is the total sum of the volume, like this

(This is of course just overlaying two charts)

Any way to do this with one chart using dimensionality, or some other fancy magic?

Thanks for you time!

[Taoufiq_Zarra · Accepted solution]

attached two propositions :

1-> ui

2->Load Script

[mellerbeck]

Ahh, clever!