In the finance window, the "margin" is shown (correctly) as (for example) 12.84% in the text next to the button, but shows as 1,284 in the graph suggesting that there is a missing "/ 100" somewhere.
That is intended, since other paks with margins smaller than 1 percent would just be shown as 0.
Can you not just show it as a decimal, e. g. 0.67?
It could display as money, although it would get the money symbol.
It is also certainly possible to code percentage support into the graphs, but as with everything else, someone has to have the time and motivation to do it.