Though, I'd argue it should be 18 years free by their math. They lump a subset of leisure activities into another category as if those are beyond your easy control.
Commuting, working, grooming, etc - sure, you could optimize those, but it's harder to deviate from the norm. But TV/video games? Doesn't seem like the same discussion.
https://www.visualistan.com/2015/02/what-do-7-billion-people...