University High School ranked higher on The Washington Post‘s 2014 list of America’s most challenging high schools, rising to No. 1,502 nationally. That’s up from last year’s ranking of 1,671.

Read more about the Post‘s America’s Most Challenging High Schools list, or see the complete listing of schools. You can also check out U-High’s entry in the new rankings.

Only 9 percent of the approximately 22,000 U.S. public high schools earned placement on the list. America’s Most Challenging High Schools ranks schools through an index formula that’s a simple ratio: the number of Advanced Placement, International Baccalaureate and Advanced International Certificate of Education tests given at a school each year, divided by the number of seniors who graduated that year.

Learn more about how the list is compiled.