The U.S. Census Bureau estimates Alabama gained 17,340 residents in the 15 months between April 1, 2010 (Census Day) and July 1, 2011.

According to Annette Watters, manager of the State Census Bureau at The University of Alabama, Alabama is the 23rd most populous state in the nation.

“We are a mid-sized state, both in territory and in population,” Watters said.

The Census Bureau estimates that in July 2011 Alabama had 4.8 million people.

Watters said the South is the fastest growing region of the country, “but Alabama is not the fastest growing state in the South. As a whole, the South grew mostly because of people moving into the region from other states.”

The Northeast and the Midwest have been losing residents to the southern part of the country, but Alabama hasn’t been attracting these domestic migrants as fast as some of its sister Southern states, Watters noted.

In addition to migration, a state’s birth rate can increase the state’s population, and the South and the West have had the highest birth rates since Census Day. But, for the past year, Alabama’s birth rate has been below the average for the South, and even below the national average.

“In times of trouble, people think twice before having a baby,” Watters said, and “Alabama had some well-reported troubles in 2011.” The year 2011 was a tragic year in many parts of Alabama -natural disasters, economic disruptions, newsworthy legal issues, home and family instability.