True, although I'd guess that the massive decrease in mortality in infants under 1 (who are still massively more likely to die than older children) is probably due to improved medical intervention.

For older children and teenagers it's probably better safety equipment, particularly in cars. I guess we've also got improved treatments now for the few diseases which actually do kill children, such as various cancers.

But hey, it's still good news, even if "healthier" isn't the way to describe it.