It would be pretty hard to go solo in those hours these days (7.5) when at least 20 mins of an hour lesson is spent transiting to and from a GAAP zone. Following airline style circuits (i.e way too bloody wide) you'd be lucky to get 6 touch and goes in an hour too. That was the most frustrating part of instructing, following clowns who insist on 3 mile circuits in a 172.
When I was instructing the usual seemed to be 15-20 hours with people more often than not in the high teens.
If I had my time again I would have gone to a small school in the country and believe I would have saved at least 30 hours on my CPL training. (exercises like doing 7 hour Mooney endorsements and all the other BS that is thrown at you tends to soak up a few resources)