Interesting question...for me it seems that the average size I catch varies from year to year. While some days in every year have more fish that are larger than normal, it seems like some years those days happen a lot more often. For example, in 2004 I caught a lot more 10-12 inch trout than I did last year. One day in particular the small fish were about 8 inches and the average was probably 10. I dunno if it is just me or maybe it has something to do with the class years in the stream
Anyone else experience this?