Harborfields High School has been named to The Washington Post’s annual list of America’s Most Challenging High Schools in the United States. In this year’s Challenge Index, Harborfields High School is ranked No. 3 in Suffolk County, No. 13 on Long Island, No. 33 in New York State and No. 387 in the nation.

In order to calculate an index score for each school, researchers take the total number of Advanced Placement, International Baccalaureate and Advanced International Certificate of Education tests given at a school each year and divide it by the number of seniors who graduated in May or June.

Public schools that achieved a ratio of at least 1.00, meaning they had as many tests in 2013 as they had graduates, were put on the national list. Schools are ranked in order of ratio. Only 9 percent of the approximately 22,000 U.S. public high schools managed to reach the standard and earn placement on the list.

“This ranking is a testament to the hard work of everyone here at Harborfields, with special recognition for our teachers and our community,” said high school Principal Dr. Rory Manning. “Our students challenge themselves with the most rigorous classes because they know that the special person in front of the room will be there for them and lead them to success. We also know that support for our educational achievements begins at home. Our school would not be the quality school that it is without the support of our parents.”