Bill, I think that's about where mine are in length. I stocked my YP in the spring of 15, and have had the feeder running most of the time. I need to get a ruler down at the pond to get actual length measurements. I'll do that today, as we will be catching some more. Last night the 2 yr old twins (grandkids) were catching fish faster than I could bait hooks, and put the fish in the basket. Caught mostly HBG, but did manage to bring in six YP. I'd say they were all 8-9".
I've got to admit, the HBG have grown to twice the weight of the YP, and put up three times the fight, but the YP are easier to clean at 9:00 at night, and taste the best. If my HBG weren't half piranha, I'd be a bit happier with them.
Caught several more yesterday. Maybe it was juggling the 2 yr old twins, my daughter, my mother in law, and my crazy Drathaar. I didn't measure a single one. My water temps are still pretty cool, so the YP are still hitting.