Once the sample has been selected and fielded, and all the study data have been collected and made final, a poststratification process is used to adjust for any survey nonresponse as well as any noncoverage or under and oversampling resulting from the study specific sample design. Poststratification variables included age, gender, census division, race/ethnicity, and education. The weighted data reflect the U.S. population of adults age 18 and over.