First image shows that income tax for city Dioclea is 6.85 while second screen shows a value of 6.22.
I was able to calculate city tax value using the formula provided in the wiki and I got value of 6.22.
Also the values differ for other cities as well but I noticed the difference between these two values is small.
Why is there a difference between the two screens?
Note: I am playing base game without any DLC activated.