According to this map, red counties saw a decrease in the percentage of their populations under 25 in the last decade. Please note, each county in District 13 (except Lee County) is in the red. Conversely, during the same period, District 13 increased the percentage of those over 65.
As shown on these maps and discussed here, this trend is nation wide. As I argued here, “only when we restore strength and vigor to our local economies will our best and brightest have a reason to return home.”