I don't know if anyone ever attempted to create a statistic about the litterers to non litterers ratio. It's true that people who litter do exist but if their numbers were overwhelming, we would be swimming in refuse by now. My guess is that those who litter are greatly outnumbered by those who don't. It's just that the pieces of garbage casually tossed out on the grass are so "in your face".
If we assume that the number of people who don't litter is far greater than of those who do, we would conclude that the problem of littering would be solved if every single non-litterer picked up at least one piece of garbage while out in the wild. Especially plastic.
To say "I don't litter" is not enough. If I pass by garbage on a trail and don't pick up at least one piece, it's only one notch better than littering and it's almost like turning a blind eye on something evil.
Let's move it up to two notches!