A more descriptive statistic to me would be the percent of owners of hybrids vs. gassers of a certain year that still have their cars.
Say... for 2006, x% of hybrids are still original owner, y% of gassers (of a similar class!) are still original owner.
That'd be much more telling to me.
2004 Honda Civic Hybrid "Eeyore" @ 49 mpg
-MaxIMA, OBDIIC&C, IMAC&C, Lower grill block
RIP 2000 Insight, 40k miles @ 69.2 mpg
2000 Insight, AKA "The Basket Case" or "The Go Pod" @185k miles @ 63.5 mpg
-IMAC&C, OBDIIC&C, Scott's aero panel, grid charger, cheapo sound system