I'm pretty sure I've found them on all the moderns. Mostly P mints, obverse and reverse, one coin has them with eight different off-sets. Some are too faint to photograph (for me) but they are definitely there. I have 2014, and 2015 major trail dies like the 2013, but faint. It's kind of crazy how I just keep finding them. I do look at nickels more than any other denomination. Went through a spell of clashes like that too.