Pretty much every single year. Originally, I was just one of the chaperones, but as the program developed I became the lead chaperone. So, now it's pretty much me and a second first-time teacher at my school (my wife's also been twice but only once with me.) We do have a sort of unwritten rule that students may only go a maximum of 2x and they need outstanding teacher refs to even consider going between 9th and 10th grades. It's pretty cool for me to see former students now living in Japan or attending school there. Matt, who you can see in some of the pix is a paralegal in Roppongi and a student at Keio University. He has accused me warmly of "changing his life"--trust me, that as a teacher no amount of $$ can ever equal something like that!