The number of hours to solo probably says at least as much about the type of helicopter, the instructor, and the school, as it does about the student. R22s are incredibly twitchy and people take a long time to learn to fly them...but after that they can convert to any other type easily.
However, this means time to solo tends to be longer than with other types. In the USA, I believe you're not allowed to solo an R22 with less than 20 hours on type, and some flying schools elsewhere have decided on that too. Also, some instructors/schools are happy to send you solo when you can just about totter round the circuit and hover, while others want to make sure you can do engine-off landings safely, and handle other emergencies. Then there's the weather, how busy the airfield is, availability of instructors and machines etc etc. This means that some people do most of the course before going solo. I did, and it meant I kept getting sent out afterwards to make up my solo hours, being told by my instructor, "Go where you like, but fly slowly as you need the hours!"
But whatever you do, please don't get hung up on hours to first solo; it'll make your flying training very miserable when it should be great fun