Public schools are ranked according to a ratio devised by Jay Mathews: the number of Advanced Placement, Intl. Baccalaureate and/or Cambridge tests taken by all students at a school in 2007 divided by the number of graduating seniors. All of the schools on the list have an index of at least 1.000; they are in the top 5 percent of public schools measured this way. E and E % stands for equity and excellence percentage: the portion of all graduating seniors at a school that had at least one passing grade on one AP or IB test.