I got this info from here (Wapedia). It made me giggle...
Multi-time winners of the award include Sara Douglass (three wins), Juliet Marillier (three wins), Garth Nix(two wins), Jane Routley (two wins), and Sean Williams(two wins). Sara Douglass holds the record for most nominations, and Glenda Larke has the most nominations without winning, having been a losing finalist four times.*
Lol!! It will probably go up this year as The Last Stormlord is my fifth short listing...
* Technically, the use of the word "nomination" is incorrect here. Any book which is eligible can be nominated and usually is. Thus what I have is the most short listings without winning.