Younger teachers are definitely more likely to have worked at charter schools as opposed to have just heard of them. Charter schools explicitly look, often, to hire younger people. I've even talked to people who didn't necessarily go into teaching thinking they wanted to work at a charter school or even may have been considered critics of the charter school movement, and found that it was the only way for them to get their foot in the door. So young people just have much more familiarity with the concept.