I brought this up to show that the I have received 10x the education from the code I have written professionally than from all my formal schooling.
I realize as well as anyone here that the best code usually have less lines. At least mine does. But "years of experience" has less meaning, believe me. So do title, company, number of jobs, number of customers, etc., etc., etc.
Just like in basketball, there is no substitute for height, in programming, there is no substitute for actually having written code.
I realize "Lines of Code" isn't a great metric, but it's probably the best to quickly communicate my point.
Spending a few months working on hard problems without a functional debugger can compleatly change how you aproach programming. But, so does finaly understanding how to use a debugger. Spending a few weeks reading other peoples code to document a working system was also an incredably valuable experence.
PS: The closest thing to a single nuber I can think of is "how many diffrent months of experence do you have?"