Earlier rates are on a cohort basis.
Race-specific data for 1995 and 1996 are weighted to account for unmatched records. These two factors affect numbers of events, composition of the Hispanic population, and maternal and infant health characteristics. Rates for race groups from the National Linked Files of Live Births and Infant Deaths vary slightly from those obtained via unlinked infant death records using the National Vital Statistics System because the race reported on the death certificate sometimes does not match the race on the infant's birth certificate. Centers for Disease Control and Prevention, National Center for Health Statistics, National Vital Statistics System , National Linked Files of Live Births and Infant Deaths . 1997 data are from the National Vital Statistics System.