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.
| Not Suitable | Marginally Suitable | Moderately Suitable | Highly Suitable |
| 42.6 million km2 | 21.0 million km2 | 28.6 million km2 | 4.6 million km2 |
