Many babies born prematurely have caught up with their peers by the time they are two years old. (health-and-parenting.com)
These kids end up being left behind and they can experience a hard time catching up with their peers once they join an elementary school. (checkpregnancy.com)
If a class of people starts with a low base rate salary, even high percentage raises will not allow them to catch up with peers in other groups. (sciencemag.org)