In the 50 years from 1960 to 2010, the global labor force’s average time in school essentially tripled, from 2.8 years to 8.3 years. This means that the average worker in a median country went from less than half a primary education to more than half a high school education.
从1960到2010年这五十年里，全球劳动人口的平均在校时间从2.8年增长至8.3年，基本达到原来的三倍。也就是说一个中等国家的普通工人从还差一点完不成一半的小学教育演变成今天的完成高中教育的一半以上。