Interesting, if trivial analysis from NCSL on the age of state legislators. Only 4% of legislators nationally are under age 34.
They also have a tool with demographic profiles of legislators in every state. Pennsylvania matches the US average with 4% of lawmakers in the young category (and I define “young” as my age or less, a category which is every growing). The tool also includes, gender, ethnicity, religion, and occupation – not surprisingly, almost 80% of Pennsylvania lawmaker list their occupation as “full-time legislators”.