It depends on the day. Rec classes are generally 7:1 or better.
For team, it could be as high as 16:1, but if that is the case, it is only one group and there is often a "float" coach that can step in to any of the groups.
Typically though:
Level 3 - 11:1 or better.
Level 4 - 9:1 or better
Level 5 - usually mixed with Level 4 at 15:2
Level 6+ and Xcel - 16:1, but they are rarely all there and 4 are currently out injured, not all gym related... so currently 12:1 or better.