Source for 2012 national data: National Occupant Protection Use Survey (NOPUS), 2012. Source for 2012 state data: State Observational Survey of Seat Belt Use, 2012. Source for 2014 national data: National Highway Traffic Safety Administration's (NHTSA) National Occupant Protection Use Survey (NOPUS), 2014. Source for 2014 state data: National Highway Traffic Safety Administration's (NHTSA) State Observation of Seat Belt Use, 2014