I have a feeling that most home schoolers are religious, I would think that religion is a prime motive for home schooling. But home schoolers, IMO, do better because the public schools do an appalling job, for the most part, and because the home schooling parents really care and they make darn sure that the kids get an education. I don't begin to know what home schoolers teach concerning evolution, but I have a feeling they do cover it, possibly as a theory.
Non religious parents who really care often send their kids to private schools if they can afford it, where they also do lots better than the public school kids.
Being a religious parent who homeschools also does not equate to teaching creationism and not teaching evolution. Many religious people would not refuse to teach their children evolution, since many religions, such as Roman Catholics, do not see evolution as contrary to their beliefs.