Tabular data are broken down by year (1974, 1975, 1977, and 1979); by type of facility (open or institutional); and by State (50 States and the District of Columbia). Preliminary data show a 3-percent decrease in the number of privately operated juvenile custody facilities between yearend 1977 and 1979, indicating a slight reversal after a one-fourth increase between 1975 and 1977. All but 5 percent were long-term or postplacement establishments. A 2-percent reduction in resident population centered on status offenders, pointing to continued efforts to deinstitutionalize juveniles in this category -- a key objective of the Juvenile Justice and Delinquency Prevention Act of 1974. As was the case among facilities operated directly by government agencies, the decrease in juveniles was entirely among girls, whereas the count of boys showed a small increase. The ratio of committed to detained youth rose from 26 to 1 in 1977 to 30 to 1 in 1979, further strengthening the private sector's principal role of providing postadjudication care for committed juveniles. At the end of 1979, only 2 percent of private facilities were being used at more than 100 percent of design capacity, and almost a fifth were less than 70 percent occupied. Population declines were reported in about half of all States during 1977-79, following gains in approximately three-fifths from 1975 to 1977. Illinois, Washington, and Minnesota registered the largest decreases in juveniles, whereas Pennsylvania, Arkansas, and Tennessee were the leading gainers in absolute numbers. (Author abstract modified)