Hey Kirill!
That chart shows the median across everyone Insights counts as active that week. Review bots are in that set. CodeRabbit was already reviewing. Starting the week of Sep 14, Copilot, Macroscope, and Graphite's review app also left reviews, and none of them merge PRs. With those zeros in the set, the median engineer is 0.
You should still be able to view your PR count at the bottom of the page.
Hope this clears up the confusion.
Brett B
Graphite Support