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.
Solid bars correspond to median values; semi-transparent rectangles correspond to 95% confidence interval. The vertical axis is log-transformed. Asterisks (*) indicate cases for which p < 0.05.
