Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Patterns of sleep duration at 2.5, 3.5, 4, 5 and 6 years of age:: short persistent sleepers (n=109; 6.0%),: short increasing sleepers (n=88; 4.8%),: 10-hour persistent sleepers (n=920; 50.3%), and: 11-hour persistent sleepers (n=712; 38.9%). Predicted (dashed lines) versus observed (solid lines) trajectories. Data courtesy of the Quebec Institute of Statistics.
