What percentage of sleep cycle do infants spend on REM how about adults?

The percentage of time spent in REM for an infant of 1-15 days is about 50% and 3-5 months: 40% and 6-23 months: 30%. The percentage continually decreases as age increases, but many adults tend to keep themselves in REM sleep for about 20-25% of sleep. Again the older people are the less they are in REM sleep and older adults from the ages of 70-85 may drop the amount of time in REM below 20%.