不夠睡

看到這麽一個報告：

The trend in industrialized nations over the last hundred years suggests that people are increasingly sleep deprived. In 1910, the average person slept 9.0 hours a night. By 1975, the total had fallen to 7.5 hours. The 2002 Sleep in America poll, conducted by the NSF, indicates that the average American adult now only sleeps 6.9 hours a night, leading to fatigue, exhaustion and other symptoms. Shift workers suffer more than other people: many shift workers average only five hours a night.

1910年：人均睡眠時數是9.5小時/天
1975年：人均睡眠時數是7.5小時/天
2002年：美國人均睡眠時數是6.9小時/天

工業化的結果是，人類的工作時數增加、玩樂時數增加，只好睡眠時數減少。