G.B.
At a licensed child care center in Oklahoma a teacher may have 4 babies, 6 toddlers from age 12 months to 23 months, at 2 years of age the class size increases to 8 per teacher, then to 12 in the 3 year old class, and 15 in the 4 year old classroom, then up to 20 school agers for each teacher.
If you have the money then be selective when picking a center out. If you are looking for education then don't even send them until later. At 2 years of age they are working on potty training, sharing, not throwing food at the table, using flatware, experiencing different things like textures, finger painting, playing in whip cream on a flat surface, learning to color, etc and getting lots of play time. When a child is a full 3 years old they are more ready for a classroom situation like a serious pre-school setting. They are able to focus more on tasks such as doing a craft without help, or minimal help, practicing writing their name, learning about weather, seasons, pre-counting skills, pre-reading skills, etc...so it depends on what your expectations are. Do you want just some interaction with other kids? or a full pre-school setting?