DES MOINES, Iowa (AP) – Officials say Iowa student scores have dropped in statewide reading and math tests. The Des Moines Register reports the percentage of Iowa fourth-graders on grade level in reading fell to 74.8 percent last spring from 75.7 percent during the 2014-15 school year. In math, fourth-grade proficiency fell to 79 percent this year from 80.3 percent in 2014-15.

Jay Pennington is the Iowa Department of Education’s bureau chief of information and analysis services, and he says the tests are only one measure of success. Until this school year’s tests in spring, results on the Iowa Assessments have increased every year since the accountability exams were begun in the 2011-12 school year.

Officials say it’s unclear why there were drops for the 2015-2016 school year.