[brucepick]

Yes - it's actually a million registered vehicle-years. A million vehicles registered for a year. Two million registered for a half year = same as half a million registered for two years. So the published numbers are a pretty good reflection of cars being on the road. If all cars were driven the same distance annually then it would be a very even comparison. So the study just assumes that the driven miles average out within each model. They group together same-design model years that fall within whatever years are included in each published study. Such as the '96 - '00 Civics could be considered together.

The layout and text look exactly like the IIHS data I've seen and saved. Insurance Institute for Highway Safety, iihs.org.