The U.S. Education Department is sending Arizona more than $648,000, to help defray the costs for low-income students to take Advanced Placement, or AP exams.

The state’s been receiving this grant since 2003, but this year’s amount is the most it’s ever gotten; officials say since they started getting this money, the number of tests it’s helped pay for has risen from less than a thousand to more than 16,000.

Peter Laing is senior director for Advanced Placement programs at the Arizona Department of Education.