Since Super 12 started in 96, 3 SA and 4 Aus teams won. 8 SA, 6 Aus, and 1 Argentine teams were runners up. Only 3 NZ less finals, 2 of which were all SA. No all Aus finals
Probably cause the NZ teams usually dominated the Super 12/14. Occasionally an Aus or SA team would have a good year, but it was usually the NZ teams winning.