It's been a couple of years since I worked in day cares, but I remember the school age ratio being 26, and I think my 12-18 month ratio was 6:1(?). At the end of me working in day care, Texas came up with this weird formula. You wrote down all the kids in the class with their ages, you then divided the number of children in half. Then you counted down the list that number and what ever age the child was you landed on was the age that you went with. So, if you had 20 kids and the 10th kid on the list was 7, you went with that ratio.
My best advice to parent is to show from time to time unannounced to just check in on your child. If you can peek into the class where they can't see you, so it doesn't upset your child when you don't take them with you. Know your ratios, and make sure they stick to it. Also ask how they did on their last state inspection and check with the health inspector.