While a lot of us are happy to have 3 year dried oak, you have us beat by a lot. Overachiever! I think the oldest I’ve burned was 4 years dry. This year I’m burning 2 year old oak but it was dead and in the mid 20s M/C when cut.
IIRC 40 something… but I could be way wrong. I remember checking a fresh split years ago but don’t remember exactly