First solo will probably come quicker if you are (a) flying every day, doing your PPL in a solid block, and (b) younger. Being older, distracted by other cares (work, family, etc) and going once a week or less frequently, will make it take longer.
For example, I did my PPL at Lydd, aged 17, on a Royal Navy Flying Scholarship, and was one of the last on the course to solo, at 8 hrs 40. If you didn't make it by 9 hrs, they could boot you off the course.
I've not met anyone in Australia who soloed in anything like that sort of time - most are probably 12-25 hrs. But that probably reflects the fact that most of the students here are older, and doing it part time between other committments.