Two bar graphs showing total sleep and percentage of sleep in REM for people of different ages. The graph on the left shows total sleep per day in hours ranging from 0 to 16 hours on the y axis. The x axis shows various age ranges. Newborns from 1 to 15 days old sleep the longest, about 16 hours per day. As the ages increase, the hours slept gradually decrease to 6 hours for adults aged 70 to 80 years. The graph on the right shows percentage of sleep in REM ranging from 0 to 50 percent on the y axis. The x axis shows various age ranges. Newborns from 1 to 15 days old spend the most time in REM, about 50 percent. Times spent in REM decrease with age until reaching a minimum of 20 percent during ages 5 to 13. Then time in REM slowly increases to 25 percent from ages 19 to 30. It slowly declines again, reaching 15 percent at ages 70 to 80.