Figure 3.
Two-week frequency averages by subjects with (A) upward trends, (B) no change, and (C) downwards trends.
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.