Data for School year-end 1994 through year-end 2020. State oral health surveys are the data sources for these indicators. States periodically conduct independent screening surveys of a probability sample designed to be representative of all third-grade students in the state. Some states also conduct surveys of students in other grades in school, or of Head Start program enrollees. This surveillance activity is voluntary. States submit their data to the Association of State and Territorial Dental Directors (ASTDD), where the survey design and data collected are reviewed for quality and against the criteria for inclusion in NOHSS, before being sent to CDC for inclusion in Oral Health Data. For more information, see: http://www.cdc.gov/oralhealthdata/overview/childIndicators/