Human life expectancy barely changed before the late eighteenth century. Yet it is difficult to overstate the magnitude of the gain since 1900: in that year, life expectancy worldwide was 32 years, compared to 69 now (and a projection of 76 years in 2050).
全世界健康指标显示出一些最大的改善。人类寿命预期在十八世纪末之前鲜有变化。但自1900年以来，这方面的收益不可谓不巨：1900年全世界寿命预期为32岁，如今为69岁（2050年的预测值是76岁）。