For the 2012 model year, for example, NHTSA said it tested 74 vehicles, including 42 passenger cars, 22 sport-utility vehicles, two vans and eight pickups. The agency says that crash tests will provide information on about 81 percent of 2012 model-year passenger vehicles sold in the United States, while rollover tests will provide information on 92 percent of the 2012 fleet.
The Insurance Institute for Highway Safety (IIHS), a private nonprofit organization funded by automobile insurance companies and insurance associations, conducts its own testing program and issues its own ratings. NHTSA and IIHS conduct different tests, and neither organization tests all cars on the market. But they do test the volume sellers. IIHS also made it a point in 2011 to test such innovative cars as the all-electric Nissan Leaf and the plug-in hybrid Chevrolet Volt.
Here are NHTSA's Five-Star safety ratings. Note that you can't compare 1990-2010 vehicles with those from 2011 forward. Starting with 2011 models, NHTSA introduced tougher tests and new ratings in its Five-Star system. The agency says they provide more information about vehicle safety and crash-avoidance technologies.
The IIHS ratings page includes the testing information for individual cars. You can see which vehicles earned IIHS's "Top Safety Pick" designation.