you've got a pair of fish with one albino parent and one normal parent and both have a copy of the normal gene and the albino gene. this should result in a 75/25 ratio (normal/albino) but there may be more than one gene involved in your case, but I doubt it.
albino fish are quite rare - most get eaten before they can breed. Lots of the albino fish in the hobby are the result of hybrids of albino fish X with closely related species Y, and then the XY hybrids with the albino gene get crossed back with pure species Y a bunch of times, but the breeders are careful to keep the ones that still carry the albino gene.