Teachers technically have summer off, but they manage to log almost as many hours working as your average full-time employee. According to Organization for Economic Cooperation and Development data from 2008—the most recent data available—American teachers work an average of 1,097 hours per year on instruction, ranking U.S. primary-school educators the most productive among major developed countries. The data tracked 27 nations and found that despite only spending 36 weeks in the classroom each year—among the lowest of all the countries tracked—U.S. teachers worked the most hours—100 more than New Zealand, which ranked second in the survey, although the school year in New Zealand is three weeks longer than in the U.S. But student achievement doesn't match up: U.S. student progress in reading and science remains average compared with other nations, and slightly below average in math.