Your point about there being a difference between immigration and net migration isn't relevant to the question that was asked and answered.
And when I said '12 years under the same calculation method'; I accepted that the pre-June 2012 data was calculated differently, so I have discounted the 2011 data and have instead used the data that was calculated under the same method (June 2012 onwards).
When you calculate the 12 published figures from Q2 2012-2023, the total is 3,493,000, which works out as an average yearly net migration figure of 291,083.