If someone was at the far end of your stated age range and then had kids when they were 20-25; those kids would be between 15-20 years old.
If your talking about those kids - let's say age range between 10-15 when they are sitting in front of the TV instead of outside playing; those kids would have been born to parents born between 1970-75 - so outside of your stated age range?

Just busting on you hawkesaurus......it is BOTH of their faults - no matter what the age (of the parents or the kids); but there is little doubt in my mind that kids are more content to stay indoors today. There is just more to keep them inside nowadays. When I would make sulphur volcanoes in the house with my chemistry set - my mom kicked me outside for the rest of the day

USMCFLYR