According to data from an OCDE study, Japan and Korea are the countries in the world that sleep the least hours, 469 and 470 minutes per day respectively, around 7 hours and 50 minutes. The French are the ones that enjoy more sleep time (8 hours and 50 minutes), while Americans get to sleep also quite well (8 hours and 38 minutes). My home country Spain ranks 3rd in the world enjoying 8 hours and 34 minutes sleep on average every day. Maybe this data is one of the reasons why when you come to Japan you can see so many people sleeping in trains or on the streets.
How many hours do you sleep on average every day? My average, calculated during the last 3 years using the Sleep Cycle app on my iPhone is 7 hours and 56 minutes.