As a statistical tabulation based on raw data collected by the Office of Civil Rights of the Department of Health, Education and Welfare, this report presents tables of data which illustrate trends in black school segregation from 1970-1974. The statistics provide a detailed profile of the pattern of black enrollment in schools with various proportions of minority students (American Indian, Asian American, Spanish Surnamed American, and others). They show the number and percentage of black students and the number and percent of the district's schools at each level of segregation or integration each year. Statistics have been gathered for all fifty states according to five regions: northeast, border, south, mid-west, west. Alaska and Hawaii have been excluded. The detailed statistical profiles of 204 school districts with more than 20,000 students enrolled permit examination of trends in middle size cities and a number of major suburban and metropolitan school systems as well as the 100 largest systems (the only ones on which DHEW data was previously available). A short introduction provides historical background and analyses of school segregation. (Author/PR)