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.
Directly measured attribute values (green) are used to infer estimated values for parent nodes (orange). These estimated values are then used to fill any unknown descendant node values (red).
