Yes, but they're not evenly distributed, so its not as if you can think 'Oh, statistically, there's not likely to be another Jack in my Jack's class' with any certainty. I've no idea whether there are regional stats for name frequency, but in my own experience (lived in London when I had my son, now live in the rural Midlands), there's a far greater variety of names in metropolitan areas - related to ethnic diversity in part, but also to greater cultural self-confidence, and also of course just the fact that naming your child something 'unusual' is usual.
When my son was born, the NCT coffee mornings I took him to had babies called Soren, Thiago, Ferdinand, Ace, Miranda, Mohamed etc. at the local toddler groups in the surrounding villages where I live now, the children are named from a much smaller group of names - they seem virtually all to be Harry, George, Louis, Jack, Isabel/Izzy/Belle/Bella, Lily, Kitty, Emilia/Amelia/Millie etc.