New census estimates show that for a second straight year big cities surpassed the rate of growth of their surrounding suburbs.

Farther-out suburbs, known as exurbs, saw their growth slip to 0.35 percent, the lowest in more than a decade.

According to the census bureau , Auburn is among the top 15 fastest-growing cities in the country, with at least 50,000 residents. Auburn saw a 3.71 percent increase in population from July 1, 2011 and July 1, 2012.

Eight Texas cities made the list of 15 with San Marcos, Texas, topping the list with a 4.91 percent increase.

But, according to The Associated Press, the gains for cities in 2012 indicate that young people — as well as potential retirees — are playing it safe for a while longer in dense urban cores, where jobs may be easier to find and keep.

More from The AP: