 The real number of sacrificed victims during the 1487 consecration is unknown.Michael Harner, in his 1997 article "The Enigma of Aztec Sacrifice", estimates the number of persons sacrificed in central Mexico in the 15th century as high as 250,000 per year.Fernando de Alva Cortés Ixtlilxochitl, a Mexica descendant and the author of "Codex Ixtlilxochitl", claimed that one in five children of the Mexica subjects was killed annually.