| Age | N | Mean | S.D. |
| 18–29 | 645 | 14.2 | 6.2 |
| 30–44 | 750 | 13.0 | 6.2 |
| 45–54 | 285 | 12.6 | 6.1 |
| 55–64 | 282 | 11.9 | 6.9 |
| 65 and older | 296 | 12.0 | 6.3 |
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.