By the way, we now have even more answers: 3-5 years, 5 years, 5-6, 5-7, at least 8, and 10-12. I'm not gonna count the thirty, which must be a mistake.
Perhaps your pond will be a significant additional data point.
You could tag or fin clip any of the large ones you catch now from your known age class. If they are ever caught again, or found dead floating, then you would be able to readily report their age. (You need to mark the later age class differently, and perhaps mark any new ones you add during your next HSB stocking.)
The other option is to test the otoliths if you catch a really big one a decade from now and determine its true age.
(Do we have anyone on the forum that could do that if you minimally prepared the sample correctly?)
