However, depending upon the data being examined, the fluctuation may be smaller. Standard errors are shown below for various percentages. The average number of hours slept on both weekdays and weekends has remained consistent since 1998. Also, the percentage of the population reporting various amounts of sleep time has remained very stable during this period of time. The amount of sleep obtained during the workweek is strongly related to the number of hours worked each week.
Caregivers report a lower average amount of sleep than do non-caregivers.
Frequency of sleepiness interfering with respondents' daily activities remains consistent with responses found in previous years. The number of hours of sleep each night is a predictor of daytime sleepiness. The fewer hours slept, the higher percentage of respondents reported sleepiness at a level that interferes with activities at least a few days per month. Respondents were asked to rank the activities most likely to be given up due to lack of time. Leisure activities were likely to be given up most often because there was not enough time, followed by job-related work.