The average composite score on the ACT college admissions test dropped to their lowest levels since 1991, according to data released this week.

The average composite score fell to 19.5 out of a possible 36 for the class of 2023, according to the nonprofit ACT.

"This is the sixth consecutive year of declines in average scores, with average scores declining in every academic subject," ACT CEO Janet Godwin said in a news release.

The proportion of what ACT calls "Covid cohort seniors" who did not meet any of the benchmark scores considered necessary to succeed in college reached a historic high of 43%.

The average scores in math, reading and science were below the ACT College Readiness Benchmarks, the nonprofit said.

"The hard truth is that we are not doing enough to ensure that graduates are truly ready for postsecondary success in college and career," Godwin said.

ACT said just 21% of students met all four benchmarks -- English, math, reading, science. The benchmarks are the minimum ACT scores required for a student to have a high chance of success in first-year college courses, the nonprofit said.

"We are also continuing to see a rise in the number of seniors leaving high school without meeting any of the college readiness benchmarks, even as student GPAs continue to rise and students report that they feel prepared to be successful in college," Godwin said.

Roughly 1.4 million high school seniors from the class of 2023 took the ACT test, an increase over the 2022 graduating class.

Godwin said the problems facing high school students are systemic. Solving them, she added, would require sustained action and support at the policy level.

"This is not up to teachers and principals alone -- it is a shared national priority and imperative," she said.