In a 2007 analysis, IIHS found that 50 percent of fatalities in small four-door vehicles were single-vehicle crashes, compared to 83 percent in very large SUVs. The Mini Cooper had a driver fatality rate of 68 per million vehicle-years (multi-vehicle, single-vehicle, & rollover) compared to 115 for the Ford Excursion, which has a high proportion of fatalities from vehicle rollover. The Toyota Matrix was even lower at 44, while the rollover-prone Chevrolet S-10 Blazer 2 door was 232. The Nissan 350Z sports car (193) and the mechanically similar Nissan Altima sedan (79) show that driving style can't be isolated from engineering in these results. The analysis' conclusions include findings that death rates generally are higher in lighter vehicles, but cars almost always have lower death rates than SUVs or pickup trucks of comparable weight.