Idaho high school students showed improvement on Advanced Placement tests, but lag well behind national benchmarks on the SAT college placement exam.

Those are two key findings from national results issued Tuesday.

The College Board, a New York-based nonprofit, released scores for the three sets of tests it administers: the AP exams, the SAT and the PSAT/NMSQT, a practice test for the SAT.

Here are the Idaho results:

• AP: More Idaho students are taking the AP tests - challenging exams which can translate into college credits. And more students are getting passing grades.

In 2014, 11.1 percent of Idaho's juniors and seniors took at least one AP test, an increase from 7.3 percent in 2004. This year, 7.5 percent of 11th- and 12th-graders scored at least a 3 on the AP's five-point grading scale, increased from 4.9 percent a decade ago.

Those improvements also translated into low-income households. More than 18 percent of the Idaho students who passed an AP test come from low-income households, increased from 7.5 percent in 2004.

"Idaho has made a great commitment to expanding access to challenging course work for students across the state," the College Board said in its report.

Despite the gains, Idaho still lags behind the national averages - both in participation and passing grades.

• SAT: Participation is high, because Idaho allows all high school students to take the SAT for free in April of their junior year.

Scores are spotty, however. Only 25.7 percent of 2014 graduates scored a 1,550 on the SAT's 2,400-point scale - the College Board's benchmark used as a predictor of success in college. Nationally, 42.6 percent of students hit the college-ready benchmark, a result which has remained stagnant.

The Press recently reported that the average overall score reported statewide is 1,363. In Kootenai County's largest school districts, the average scores are: Lakeland, 1,434; Coeur d'Alene, 1,420; and Post Falls, 1,406.

Idaho's results are not surprising, according to the College Board. As more students take the SAT, the percentage of students hitting the benchmark tends to decrease.

Idaho students are required to take a college placement exam in order to graduate. Most choose to take the SAT, since it is offered at state expense.

• PSAT: Here again, Idaho's participation is high. Nearly 82 percent of the state's public high school sophomores took the PSAT in 2013, compared to 38 percent nationally.

This is important, according to the College Board, since a strong score will help identify a student who is likely to succeed in an AP class, while a low score can help identify a student who needs to get back on track.

Idaho students are also able to take the PSAT at state expense.