[ Law & Ethics ] Open Question : What can I reference when asking for a cost of living increase in California?

My contract entitles me to renegotiate my contact at the end of every year, and also entitles me to a cost of living raise (if I ask for it). I am coming up on the "end of the year" for my contact, and was wondering what I can reference when asking for a % raise. I live in Los Angeles, CA and work in Beverly Hills, CA.