I haven't actually come across that many SJs my age. There's one living on my corridor, an ISFJ and one of the nicest guys you'll ever meet (stacked like a brick), but he's one of the few SJs I've met and the only ISFJ I've ever met. Most people my age are EPs and IPs.
However, the OTC (Officer Training Corps) has given me access to a variety of people who could easily be EJs. There's one guy I'm sure is an SJ in my platoon, for example.
As an SJ, whether you're a teen or not, how likely are you to cross paths with another SJ? Who are you most surrounded by?