2018 Pittsburgh, Pennsylvania 2017 Atlanta, Georgia 2016 San Diego, California 2015 Arlington, Virginia 2014 Kansas City, Missouri 2013 Denver, Colorado 2012 Milwaukee, Wisconsin 2011 Louisville, Kentucky 2010 Oakland, California 2009 Arlington, Virginia 2008 St. Paul, Minnesota 2007 San Diego, California 2006 Pittsburgh, Pennsylvania 2005 Milwaukee, Wisconsin
