Elderly people make up about 12.1% of the nation’s household population, according to an update of the 2000 Census.

The U.S. Census Bureau’s American Community Survey also notes those cities with the highest concentration of elderly, or those 65 and older, in their populations. They include: Boynton Beach, FL (21.5%), Lynchburg, VA (16.7%), San Francisco (14.6%), Muncie, IN (14.2%) and Philadelphia (12.7%). Phoenix, Houston, Dallas and Columbus, OH, have some of the lowest percentages of seniors.

The median age of the nation’s population jumped from 34 years old in 1994 to 36.4 years this year, according to results of the report. The ACS explores key demographic and social data for areas with populations of 65,000 or more.