When did California adopt the AMA 5th Edition, and in which California state statute is it enforced?

Under the California Code of Regulations, Title 8, Chapter 4.5, Subchapter 1, Article 7:  The California Permanent Disability Rating Schedule, is an impairment-based rating system which is based on the 5th edition and modifies ratings based on adjustments for Future Earning Capacity, occupational demands and age.  AMA Permanent Impairment 5th Edition Guide lines were adopted as of January 1, 2005, in the State of California.