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.
The horizontal line in the middle of the box indicates median; the top and bottom borders of the boxes, 75th and 25th percentiles; the whiskers, 2 SD from median; circles, outliers; and triangles, extreme outliers.
