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.
Data bars with the unlike letters represent the significance differences (p < 0.05), with the same letters represent no significance difference (p > 0.05).
