The estimated four-year dropout rate for San Diego Unified School District high school students dipped by more than 8 percentage points for the 2007-08 academic year, according to figures released Tuesday by the California Department of Education.According to the CDE, the estimated rate of ninth- through 12th-grade students dropping out over a four-year period was 9.3 percent for the 2007-08 school year, compared to 17.8 percent the previous year."Making sure our kids graduate from high school is our mission at San Diego Unified," said SDUSD Superintendent Terry Grier. "I want to salute not only our hard-working high school students, but our hard-working teachers and staff who have really pulled together (to) show solid improvement."According to the SDUSD, the improvement can be partly attributed to better data, as staff verified individual dropouts as much as possible. In past years, students who transferred to other districts might have been considered dropouts by the state, according to the district.Grier said the higher, four-year dropout rates among black students at SDUSD, at 10.9 percent, and for Latino students, at 13.3 percent, remains a concern."We continue to work from elementary to high school to make sure all of our students graduate," he said. "We should not be satisfied if one student drops out."The four-year dropout rate statewide was 20.1 percent during the 2007-08 academic year, down from 21.1 percent the previous year."I am heartened that the graduation rate is up slightly, but California's dropout rate is still unacceptably high," said California Superintendent of Public Instruction Jack O'Connell."If we look deeper into the data, we see alarmingly high dropout rates among African-American and Hispanic students," he said. "There are long-term economic repercussions from not graduating for the student, for their communities and for our statewide economy. These data provide even more evidence of the challenge and the moral imperative of closing the achievement gap as well as increasing graduation rates among all students."This is the second year the CDE calculated student graduation and dropout rates by collecting student-level enrollment and exit data.When two more years of student exit data are collected, the CDE said it will have the four years of data necessary to produce more accurate student graduation and dropout rates.