In the US, if you're graduating from high school in (May or June) 2015, you'd say:
I'm class of 2015 (pronounced: "two thousand fifteen").
Class of 2015.
I'm out this year.
I made it out (in the US one-third of high school students don't graduate, and those that do often don't know if they'll graduate until their final grades are posted just before the graduat