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.
Mean vectors (purple line) and confidence intervals (arcs) are shown. Reliable intervals appear in the same colour as the mean vector. Unreliable intervals are shown in red.
