The number of Montgomery County students who dropped out of school citing a “lack of interest” more than doubled in the past 10 years, to about 900. Montgomery leads the state in the category.

Those who quit because bad grades has grown five-fold to more than 200 last year, from fewer than 40 a decade earlier, according to statistics kept by the Maryland State Department of Education. The total number of recorded dropouts in the county was about 1,300 in 2009, down from 1,400 in 2008.