District of Columbia public and charter school students have achieved their highest marks ever on the city's standardized tests.
City officials announced the test results Tuesday. The year-to-year gains were the largest since 2008, the second year the tests were administered.
Earlier gains in test scores were tainted by allegations of cheating, although multiple investigations found only isolated instances of cheating. The school system has tightened testing security in response to the allegations.
School officials say proficiency in math and reading were up by nearly 4 percentage points apiece. Science proficiency was up nearly 2 percentage points, and proficiency in writing increased by nearly 5 points.
Chancellor Kaya Henderson says the results show the city's approach to school reform is working.