The biggest changes is in 7.0 (-30,6%) and in 3.6 (-13%). While the drift 7.0>8.0 has been around for some time and thus expected, the drop in 3.6 (amounting to 17,10% with 3.5 thrown in) could well be a result of "gentle prodding", activated lately, with users of those versions getting a note about upgrading. The increase in 8.0 - in spite of the overall drop of 3% - supports this gut feeling.
