ANN ARBOR, Mich. (AP) — Data from 700,000 high school students shows a slight drop in graduation rates under Michigan's Merit Curriculum for those entering ninth grade with weak academic skills.

The Michigan Consortium for Educational Research released the analysis Monday on the class of 2011, the first exposed to requirements that placed more emphasis on math and science.

The graduation rate for lower-achieving students dipped from 49 percent to 44.5 percent. Graduation rates for students with strong skills were not impacted. Students who were best prepared for high school had better performances in science, reading and math.

Writing scores declined for all students.

The state adopted the curriculum in 2006 to better prepare students for college. The class of 2011 is the first to have used it over all four years of high school.