Income tax collects too much from private sales

[Wixit]

(Add '.' before 'com' as I cannot post links yet)

Income tax seems to collect a disproportionate amount to its listed value, especially if private sales are involved. For example at my 10% income tax I had this situation:

i.imgur com/ZPYKX29.png

These values line up with what is in the Treasury cashflow overview screen:

i.imgur com/WkbDshg.png

However, they do not line up with what is in the Zones detail screen, where two sales are logged:

i.imgur com/K357tNR.png

Food and metals were sold and their total listed tax is only 154, but even here there is a problem as while the food tax is correct, the metal tax is wildly out of proportion at 41%. Looking at the sales the income tax should actually amount to only 60.

I do not know if it is relevant, but I have Autocracy to Burned Earth, Commerce to Corporations, and Fist to Esprit de Corps.

[zgrssd]

I'll try to repost the images: