It also is very careful not to state the total number of road casualties anywhere. If it did those roll-over number look at bit different.

From http://www.dot.gov/affairs/nhtsa1200.htm we can see that the number of road deaths in the US in 1999 (the year before, but close enough) was 41,345. This means that the 9,000 people killed when their car rolled over accounted for 25% of road deaths.

So if you were trying to take the other extreme of the argument you could say 1 in 4 of the people killed on the road were killed because their car rolled over.

Statistics say what you want them to say...