Amid sweeping educational reforms aimed at better preparing Hawaii’s public school graduates for college, the state’s average ACT composite score improved only slightly last year to 17.5, trailing the national average of 21 out of 36, according to results released Wednesday for the national college entrance exam.

The state Department of Education in 2014 began requiring all public school juniors to take the exam — which tests students in English, reading, math and science — to help assess college-and-career readiness. The ACT is mandatory statewide for public and private students in 13 states, and optional in others.

Of the 10,304 Hawaii public school students who took the ACT last year, 39 percent met the college-ready benchmark in English, compared with 64 percent nationally, and 24 percent met the reading benchmark, compared with 44 percent nationally. In math, 22 percent of students hit the benchmark score, compared with 43 percent nationally, while 17 percent hit the science benchmark, compared with 37 percent nationally.

Nationally, more than 1.9 million students in the 2015 graduating class took the ACT, representing approximately 59 percent of the nation’s graduating class.

“While the percent meeting three or four ACT College Readiness Benchmarks went up slightly from 39 percent to 40 percent, the fact remains that fully 31 percent of the ACT-tested graduating class are not meeting any of the benchmarks, which will make it difficult for them in their post-high school experience,” the ACT said in its report.

Hawaii’s individual subject scores edged up by less than 1 percentage point over the previous year, mirroring near-stagnant growth in the national averages. The state’s composite score, the average score for all four exams, increased to 17.5 from 17.3 for public school students, and to 18.5 statewide from 18.2 in 2014, while the national average stayed the same. In all, 93 percent of Hawaii’s graduating class took the exam last year.

“The improvements affirm our focus on supporting all students for success after high school,” schools Superintendent Kathryn Matayoshi said in a statement. “A sustained focus on college and career readiness is showing results for our students. We’re very pleased to see steady progress.”

Still, only 10 percent of public school students met all four benchmarks. A benchmark score is the minimum score needed to indicate a 50 percent chance of obtaining a B or higher in the corresponding college courses, which include English composition, algebra, social science and biology, according to the ACT.

“Remember as of 2014 we make all juniors take the test,” DOE spokesman Brent Suyama said in an email. “This is not a scorecard of just those interested in taking the test as a college requirement. Before 2014, we had anywhere from 2,000 to 3,900 students taking the test and the number (who met all four benchmarks) was 13 to 16 percent. Now we have 10,304 students take it.”

Hawaii revamped its education strategy after winning a federal $75 million Race to the Top grant in 2010 by pledging to pursue sweeping reforms to better evaluate teacher effectiveness, turn around low-performing schools, boost student achievement and improve instruction in the classroom. DOE officials credit the program for initiatives that have helped improve test scores, lift graduation and college-going rates, and raise the bar for quality teaching.

The state uses ACT scores as one metric on its Strive HI accountability system to measure how well secondary schools are preparing students for college and careers. The state-developed accountability system largely replaces mandates of the federal No Child Left Behind law.

View Hawaii’s ACT report at act.org/newsroom/data/2015/pdf/profile/Hawaii.pdf