If you ever wonder why Tokyoites are always sleeping on the train, a report at the 6th World Congress of the World Sleep Federation explains why: They're not sleeping enough at home.

Tokyo workers average 36 minutes less sleep every night than New Yorkers and 54 minutes less than Parisians, according to research presented at the Congress in Kyoto this month. Tokyo, it turns out, has the biggest sleep deprived population in the world.

The average sleep time for Tokyo workers was six hours, nearly 14 percent below the recommended amount. Only 23 percent of Japanese were found to get more than 7 hours, with most workers going to bed just past midnight. The habit of skimping on sleep starts early in Japan. One study found Japanese middle school students averaged just 6.9 hours of sleep per night, far below the nine hours experts recommend. Apparently, Japanese are sleep deprived most of their lives.