I just notice I forgot to add a smiley after the "Don't believe any statistics you haven't
I don't claim this graph was faked (I haven't checked, but it's most likely correct).
But it's important to realize that the scale of the graph means that for example the step you
see one month before the release of 2.6.23 can easily equal 100.000 lines of code (the
re-addition of the sk98lin driver alone were over 40.000 lines of code).
Stabilization, also known as bugfixing, tends to consist of small patches (usually < 100 lines
changed, often even < 10 lines changed).
And these patches are simply too small for having any visible effect on a "count of lines
changed" graph for the Linux kernel.
Check e.g. http://lwn.net/Articles/274992/ for an explanation by Linus himself regarding what
causes most of the line changes later in the release cycle.