Overall, nearly 37 million young people—representing 45 percent of Americans under 20—now live in the 15 states at the bottom of the Casey foundation list. Just 15 million youth, representing only 19 percent of that same age cohort, live in the top 15 states.

Source: http://www.theatlantic.com/education/archive/2015/08/youth-population-growth-poor-outcomes/400751/