Nine Alabama high schools made this year's list of the nation's 1,900 most challenging high schools from The Washington Post.



The annual list ranks public and private schools through a "challenge index" derived by dividing the total number of college-level tests such as Advanced Placement tests administered during the school year by the number of graduates in May or June.



Thus, an index score of one means the school administered as many college-level tests in 2013 as they had graduates. Schools with a score of less than one did not make the list in most cases.



While not factored into the index score, the list also gives the percentage of students who passed at least one college-level test during the school year as well as the percentage of students who qualified for free or reduced-price lunch during the school year.



The list's creator, Jay Mathews, writes that he did not include passing rates in the formula because several schools kept their numbers artificially high by allowing only their top students to take college-level tests.



The list excludes magnet or charter schools with average ACT scores above 29.3 or average SAT scores above 2005, which are considered by the writer to exceed the highest average for any normal-enrollment school in the country.

National Rank School Location Graduates who passed at least one college level test during high school Students qualifying for lunch subsidies Index score 12 Jefferson County International Baccalaureate School Irondale 99 % 15 % 11.214 50 LAMP (Loveless Academic Magnet Program) Montgomery 100 % 11.5 % 6.907 469 Mountain Brook High School Birmingham 57.9 % 0.0 % 3.112 477 James Clemens Madison 14.5 % 18.3 % 3.111 565 Oak Mountain High School Birmingham 33 % 11 % 2.864 842 Homewood High School Homewood 46 % 27 % 2.356 1073 Alabama School of Math and Science Mobile 48 % 0.0 % 2.068 1124 Buckhorn High School New Market 37 % 30 % 2.01 1399 Bob Jones Madison 34.7 % 20 % 1.739

Updated at 12:19 p.m. April 23, 2014 to add Madison City Schools.