By the time the last pull request was acted on and 5.13-rc1
was released, a total of 14,231 non-merge commits had found their way into
the mainline. That makes the 5.13 merge window larger than the entire 5.12
development cycle (13,015 commits) and just short of all of 5.11 (14,340).
In other words, 5.13 looks like one of the busier development cycles we
have seen for a little while.
About 6,400 of these commits came in after the
first-half summary was written, and they include a number of
significant new features.

Source: LWN.net – [$] The second half of the 5.13 merge window