This fourth annual report presents data for 1991 on high school dropout and retention rates, along with time series data for the period from 1972 to 1991. The report also examines high school completion and graduation rates and includes a discussion of new data collection efforts that have direct bearing on issues of high school dropouts and graduates. The data are from the Current Population Survey to develop national event and status dropout rates; 1990 Decennial Census data to develop status dropout rates for states, counties, and large cities; and the National Education Longitudinal Study of 1988 for developing 8th- through 10th-grade cohort dropout rates. Dropout rates are presented separately for persons with different levels of income. Detailed status rate data on educational and generational levels of Hispanic American dropouts are also included for the first time. The report also contains new data on the cohort dropout rates for eighth-graders who dropped out of school between 1988 and 1990. Included is a detailed examination of high school completion and graduation rates. The report presents data, with comments and analyses, in 24 tables and 16 figures. Three appendixes contain 46 time series and standard error tables, technical notes with 2 tables, and 2 tables of 1990 Census data on dropout rates. (JB)