RALEIGH (AP) — The majority of North Carolina public school students taking standardized state exams in reading, math and science last school year failed them, according to data.

State education leaders cautioned against making year-over-year comparisons with the tests taken during a school year marked by limited in-person instruction due to the COVID-19 pandemic.

Only 45.4% of K-12 students passed the exams for the 2020-21 school year, according to results released at a State Board of Education meeting Wednesday. Two years ago — the last time testing was required — nearly 59% of K-12 students passed state exams. The U.S. Education Department did not require states to test students in the 2019-20 school year but required it this past year to assess pandemic learning loss.

Because of coronavirus safety concerns, some high school students this past year took exams months after completing the course they were being tested on. Some tests were revised, and a lower-than-normal share of students took them, news outlets reported.

“While the 2018-19 data is included as a way to provide context, comparison of the two years should only be made with a recognition that multiple anomalies occurred during the 2020-21 school year and during test administration,” state board member Jill Camnitz said.

The board also said Wednesday that North Carolina’s high school four-year graduation rate dropped slightly to 86.9% this past school year, compared to 87.6% for the 2019-20 school year. The graduation rate was still higher than what it was in the 2018-19 school year, said Tammy Howard, director of accountability services for the state Department of Public Instruction.

The test results will be used to help educators guide instruction this year. A DPI news release Wednesday said the results are indicators “of the formidable challenges that students and educators across North Carolina faced during one of the most severe disruptions to public education the state and nation have ever confronted.”

Test subjects included math and reading for students in grades 3 to 8; science for grades 3, 5 and 8; and math, biology and English for high school students.

The state did not give individual schools an A-to-F performance grade that’s based largely on state exam performance for the past year. A law signed by Gov. Roy Cooper this week legislation waves that requirement temporarily.