How often do cats spit out hairballs?

Cat hairballs are a modern day occurrence. They started when man started breeding longer hair longer hair cats. Now the frequency in which cats expel hairballs depends on the amount of hair the cat has, the more hair the more frequent the hairball.

It also depends on how frequent the cat grooms itself. The more frequent the cat grooms, the more frequent the hairball.

Also if you groom the cat frequently with a good comb you can greatly reduce the amount of hairballs. An article on hairballs can be found at the link