I currently raise Corydoras Rabauti (growing out more than 200 fry as I type this, with 150 more eggs just laid today..woohoo! =). My main female in the colony ive got has been alive and spawning for more than 12 years now. Her daughter is 10 years old, and most all of my males are between 7-10 years. She is HUGE by Cory standards. Probably a good 2.5-3 inches long, and 2inches girth when shes full of eggs. I have read many websites where people talk about their Cory cats living 15-20 years or more.
I hope yours can live just as long! =)
Good luck with them!