This report provides information on the number of students who dropped out of Colorado's public schools during the 1990-91 school year. The dropout rate is an annual rate reflecting the percentage of all students in grades 7 through 12 who leave school during the reporting period and are not known to transfer to other schools or a general education development program. In 1990-91, Colorado's dropout rate was 3.6% (9,978 students), which represents a significant decline in dropouts compared to 11,075 dropouts in 1989-90. Approximately one-fifth of the 1989-90 dropouts returned to school the following year. Also given are graduation figures for the class of 1991. The graduation rate was 79.8%, a 4-year rate based on ninth graders from 1987-88. Sixty-seven school districts (38%) had a graduation rate at or above 90%, and 31% of all public high schools in Colorado had a graduation rate of 90% or better. Data are presented in 10 tables. A final section contains questions and answers about Colorado's dropout and graduation rates and the source of information. (SLD)