

Some groups are much more represented than others in the U.S. military, and we'll start by looking at where they come from.

According to data provided by the Department of Defense, people between the ages of 18 and 24 from Florida, Georgia, or Maine, are as around twice as likely to join the armed forces than their counterparts in states like North Dakota or Utah.

Differences exist at the regional level as well. In 2013, 44% of all military recruits came from the South region of the U.S. despite it having only 36% of the country's 18-24 year-old civilian population.

On the above map, some of the lowest rates of state-by-state enlistment are in New England and the Northeast, Maine notwithstanding. The Northeast of the U.S. was the most underrepresented region of the country for recruitment in 2013: Despite having 18% of the 18-24 year-old civilian population only 14% of new enlistments came from this area.

Here's the data on state-by-state enlistment rates but grouped into regional subsets:

The Department of Defense does not have a good explanation for why some state's are more proportionally represented than others. However DoD spokesman LCDR Nate Christensen hazarded a guess.

"One reason might be exposure to large military bases in states where there are higher enlistment rates," Christensen told Business Insider.

Christensen's explanation may explain why Florida or Georgia have such high enlistment numbers, as both states are home to a large number of Naval, Marine, Army, and Air Force bases. However, this explanation does not address why Maine has such a proportionally high number of enlistees.

Others reasons, which we hope to get to in future posts on military demographics, may be that cultural or economic differences make some groups more likely to join. There may also be differences in the approach to recruiting in different areas.

"A soldier's demographic characteristics are of little importance in the military, which values honor, leadership, self-sacrifice, courage, and integrity-qualities that cannot be quantified," Sheana Watkins and James Sherk cautioned in a 2008 Heritage Foundation study of the backgrounds of U.S. servicemembers. "Demographic characteristics are a poor proxy for the quality of those who serve in the armed forces," they continue, "but they can help to explain which Americans volunteer for military service and why."

Below is the enlistment data for fiscal year 2013 provided by the DoD:

Have any insight you would care to share on this topic? Email us at military@businessinsider.com.