That's...pretty much the numbers I got. Why are we disagreeing? I said 15 years counting the time Kon was dead. This Tim is 19 - older than high school but never actually graduated. That doesn't mesh with Red Robin at the moment, but it does match up with Steph's age in Batgirl, where she's starting college (Tim and Steph were in school together for a while, so we can assume they are the same age or at least at the same grade level).