I would actually like to see that link because I have a source that says 41 max reported age. Fishbase.org
. As for the average age, it depends. Genetics also play a large role in growth and survival. There are well cared for goldfish that have only lived 10 years or even less. 25 is rather old for a goldfish, even a well-cared for one. Exact numbers are hard to pin down due to all the misinformation about goldfish floating around. The safest estimate I can come up with be between 10-20 years and even that is a large range.