Figure 3.
Connections produced by the top 15 most used relationships. The line thickness indicates frequency of use, ranging from 8 to 81.
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.