Pivot Table: adding a percentage field as '% of Subtotal'

Hello,

In the attached Excel file, there is a pivot table.

In the Data part of the table, there are two columns. The second is the exact same field than the first one but expressed as percentage (Field settings/Options/Show field as "% of" + "Total".

The problem is: I don't want to express this field as a % of Total ('Grand total') but rather as a % of Subtotal (e.g. Danemark Total).

Is this possible and how should I do it?

Any help is appreciated, thank you!

Xavier