Thats one thing I didnt do! I started to but realized "min fee per block" wasnt a good measure of overall congestion. I wanted median but thats not a standard output from bitcoin-cli. I started on a script but it was too slow and I ran out of time.
Discussion
Maybe it is also the volatility in fees too. I noticed that sellers with better prices tend to disappear when the fees are ripping up. Possibly too much risk of orders being stuck as a result of the transations being in mempool for extended periods.
Higher fees definitely makes lower value trades less worth it. But I dont think transactions get stuck much as Bisq forces higher network fees. I should make a new set of graphs considering price + mining volatility.