I would attribute that delay at least in part to the "cash for clunkers" program, which took older vehicles off the road en masse in 2009 in the US specifically. Made number go up but life a little worse, like most things we do :(

e: in case the correlation isn't clear (or you just don't feel like clicking), the program offered government subsidized and highly inflated trade in values for vehicles over a certain age and under a certain fuel economy. This greatly benefited auto manufacturers and investors at the direct expense of taxpayers and used car buyers by using government funding to essentially purchase and destroy ~half of the used car market at the time, depending who you ask.