So I was playing my chosokabe campaign again today and I was sitting on the verge of realm divide for the last 20 or so turns to build up armies, upgrades and fleets for realm divide. After building up everything I wanted and needed, my income was about 1400 koku per turn. I had a trade agreement with the Honma and Satake. The Honma were in a state of constant port blockade from the Uesugi, which pretty much nullified any trade income from them. The Satake were extremely big though sitting at 14 provinces with plenty trade ports in the east. So that brings me to my question. I started conquering provinces from the hatakeyama and triggered realm divide after which all remaining clans declared war on me. I put my taxes on very high to make sure I don't run into a surprise bankruptcy. But to my surprise, my income actually went up to 4500 koku after all trade agreements were broken. So how is this possible? I would think that my income would go down after breaking off trade agreements but apparently that was a good thing. How can I see in game how much income is actually coming in from trade with each individual clan?

Edit: for clarification, my income was 1400 on normal tax. I put it on very high and it went up to 8000. Then on the turn switch, everyone declared war on me and my income went up to 12k on very high taxes. After that on the start of the next turn I put my taxes back to normal and it was 4500.