....This state of beautiful mountains and popular ski resorts, once a magnet for back-to-the-landers, is losing young people at a precipitous clip.... Vermont, with a population of about 620,000, now has the lowest birth rate among states....The total number of 20- to 34-year-olds in Vermont has shrunk by 19 percent since 1990. [CLIP] While Vermont's population of young people shrinks, the number of older residents is multiplying because Vermont increasingly attracts retirees from other states. [CLIP] Fewer babies are being born in part because Vermont has few immigrants, who tend to have larger families...There is also a serious housing shortage,...