(CNSNews.com) - Sixty-five percent of the eighth graders in American public schools in 2017 were not proficient in reading and 67 percent were not proficient in mathematics, according to the National Assessment of Educational Progress test results released by the U.S. Department of Education.

The results are far worse for students enrolled in some urban districts.

Among the 27 large urban districts for which the Department of Education published 2017 NAEP test scores, the Detroit public schools had the lowest percentage of students who scored proficient or better in math and the lowest percentage who scored proficient or better in reading.

Only 5 percent of Detroit public-school eighth graders were proficient or better in math. Only 7 percent were proficient or better in reading.

In the Cleveland public schools, only 11 percent of eight graders were proficient or better in math and only 10 percent were proficient or better in reading.

In the Baltimore public schools, only 11 percent were proficient or better in math and only 13 percent were proficient or better in reading.

In the Fresno public schools, only 11 percent were proficient or better in math and only 14 percent were proficient or better in reading.

Among the states, Louisiana public elementary schools did the worst in teaching students math and New Mexico public elementary schools did the worst job teaching reading.

In the Louisiana public schools, only 19 percent of the eighth graders were proficient or better in math and only 25 percent were proficient or better in reading.

In the New Mexico public schools, only 24 percent were proficient or better in reading and only 20 percent were proficient or better in math.

The Department of Education’s National Center for Education Statistics describes what it means to be “proficient” in math and reading.

“Eighth-graders performing at the Proficient level should…understand the connections between fractions, percents, decimals, and other mathematical topics such as algebra and functions,” says NCES. “Students at this level are expected to have a thorough understanding of Basic level arithmetic operations—an understanding sufficient for problem solving in practical situations.”

When it comes to reading, eighth-grade “students performing at the Proficient level should be able to provide relevant information and summarize main ideas and themes,” says NCES. “They should be able to make and support inferences about a text, connect parts of a text, and analyze text features. Students performing at this level should also be able to fully substantiate judgments about content and presentation of content.”

The NAEP math and reading tests are scored on a scale of 0-500.

The average reading score for an eighth-grade public school student on the 2017 NAEP test was 265. That was slightly above the average score of 264 that public school eight graders achieved in 2015, but slightly below the average score of 266 public school eighth graders achieved in 2013.

The average math score for an eighth-grade public school student on the 2017 NAEP test was 282. That was slightly above the average score of 281 in 2015, but slightly less than the average score of 284 in 2013.