Minnesota students came out on top — again — on ACT college-readiness test scores released this week. For the 10th year in a row, state teens led the nation among states in which at least 50 percent of the students took the college entrance exam.

Being No. 1 is worth celebrating, and the 2015 scores show modestly promising trends, but overall the ACT results indicate that more work remains to improve academics among American students.

For starters, scores have remained essentially flat for too many years. Minnesota high school seniors earned an average composite score of 22.7, compared with the national average of 21, according to the ACT’s annual report. In 2006, the U.S. average was 22.1, and last year it was 22.9. With 36 as a perfect score, there is obviously substantial room for improvement.

Connecticut and Massachusetts scored the highest at 24.4, though less than a third of their graduates took the ACT. Most students in those states take the SAT exam. Nationwide, about 1.9 million students took the ACT.

Despite the high national ranking, Minnesota scores reflect a continuing challenge for the state — huge disparities between white students and many students of color. More than 46,000 students, or 78 percent of the 2015 Minnesota graduating class, took the exams. Of that group, 75 percent were white students, and they had average composite scores of 23.7.

By comparison, black students had average scores of 17.6, and Hispanic students were at 19.8. About 62 percent of the state’s white students met college-readiness standards on at least three academic subjects, compared with 17 percent of black students.

The college-readiness benchmarks indicate the level of achievement required for students to have a 50 percent chance of obtaining a B or higher in corresponding first-year college courses. National test administrators say the gaps between student groups and stagnant performance of all students are troubling.

“We’re talking about hundreds of thousands of U.S. high school graduates who won’t earn … college degree[s] because they aren’t academically prepared … ,” ACT chief executive Jon Whitmore said in a statement.

Minnesota Education Commissioner Brenda Cassellius told the Star Tribune that she was pleased that more students of color took the test. It’s also worth noting that black and Hispanic Minnesotans outperformed their peers nationally. However, those same kinds of positive signs were touted a decade ago, and clearly progress is not happening quickly enough.

As ACT officials said this week, the relatively stagnant U.S. numbers should be a call to action to improve educational outcomes. They rightly recommended these approaches: better alignment of standards, curricula, instruction and testing; more support and development opportunities for teachers, including good evaluations based on student growth, and using student data more effectively.

Locally and nationally, significant resources have been devoted to programs intended to improve achievement among all students. As the newly released ACT scores show, students of color need more effective help — from better early-education programs to more support at home and at school.