Top 100 Cities with Youngest Residents (Pop. 5000+)

From www.city-data.com:

Kiryas Joel, New York (15.0)
Monsey, New York (18.6)
Kingston, Rhode Island (19.9)
Rio Bravo, Texas (20.0)
Rexburg, Idaho (20.3)
Lackland AFB, Texas (20.3)
South Hill, New York (20.4)
Alfred, New York (20.7)
Storrs, Connecticut (20.7)
Amherst Center, Massachusetts (20.8)
Durham, New Hampshire (20.8)
Air Force Academy, Colorado (20.9)
Whiteriver, Arizona (20.9)
Highland, Utah (20.9)
Cameron Park, Texas (21.0)
Alpine, Utah (21.0)
Isla Vista, California (21.1)
Allendale, Michigan (21.1)
West Point, New York (21.1)
Twentynine Palms Base, California (21.1)
Geneseo, New York (21.1)
Durham, New Hampshire (21.2)
Oxford, Ohio (21.3)
Fort Hood, Texas (21.4)
Fort Campbell North, Kentucky (21.4)
Fort Leonard Wood, Missouri (21.4)
Camp Pendleton North, California (21.4)
Boone, North Carolina (21.4)
Athens, Ohio (21.5)
Oswego, New York (21.5)
Geneseo, New York (21.6)
Potsdam, New York (21.6)
Offutt AFB, Nebraska (21.6)
Fort Stewart, Georgia (21.7)
Clarion, Pennsylvania (21.7)
Elon College, North Carolina (21.7)
East Lansing, Michigan (21.7)
La Homa, Texas (21.7)
College Park, Maryland (21.7)
Ettrick, Virginia (21.7)
Fort Lee, Virginia (21.7)
Houghton, Michigan (21.7)
Camp Pendleton South, California (21.8)
Big Rapids, Michigan (21.8)
Indiana, Pennsylvania (21.8)
Amherst, Massachusetts (21.8)
Fort Riley North, Kansas (21.8)
State College, Pennsylvania (21.8)
Hamilton, New York (21.8)
Edinboro, Pennsylvania (21.8)
Mount Pleasant, Michigan (21.8)
Whitewater, Wisconsin (21.9)
Canton, New York (21.9)
College Station, Texas (21.9)
Hanover, New Hampshire (21.9)
Chinle, Arizona (21.9)
Blacksburg, Virginia (21.9)
Earlimart, California (22.0)
Plymouth, New Hampshire (22.0)
Fort Bliss, Texas (22.0)
Lemoore Station, California (22.0)
North Chicago, Illinois (22.0)
Kaneohe Station, Hawaii (22.0)
Minot AFB, North Dakota (22.0)
Mansfield, Connecticut (22.0)
Ada, Ohio (22.0)
Statesboro, Georgia (22.0)
Ithaca, New York (22.0)
Fort Polk South, Louisiana (22.0)
Orono, Maine (22.0)
Fort Bragg, North Carolina (22.0)
Fort Knox, Kentucky (22.0)
Eglin AFB, Florida (22.1)
Schofield Barracks, Hawaii (22.1)
Stanford, California (22.1)
Fort Carson, Colorado (22.1)
New Paltz, New York (22.2)
North Amherst, Massachusetts (22.2)
Eielson AFB, Alaska (22.3)
Orono, Maine (22.3)
West Lafayette, Indiana (22.3)
Lewisburg, Pennsylvania (22.4)
Homestead Meadows South, Texas (22.4)
Bloomsburg, Pennsylvania (22.4)
Jacksonville, North Carolina (22.4)
McGuire AFB, New Jersey (22.4)
Millersville, Pennsylvania (22.4)
Bowling Green, Ohio (22.4)
Quantico Station, Virginia (22.4)
Brockport, New York (22.4)
Fort Lewis, Washington (22.4)
Farmville, Virginia (22.4)
Lindon, Utah (22.4)
Fort Benning South, Georgia (22.5)
Fort Drum, New York (22.5)
Pullman, Washington (22.5)
San Elizario, Texas (22.5)
Monroe, New York (22.5)
Fort Belvoir, Virginia (22.5)
Williamsburg, Virginia (22.6)