Labor Code section 4660, amended effective April 19, 2004, provides:
4660(a) In determining the percentages of permanent disability, account shall be taken of the nature of the physical injury or disfigurement, the occupation of the injured employee, and his or her age at the time of the injury, consideration being given to an employee's diminished future earning capacity.
(b)(1) For purposes of this section, the "nature of the physical injury or disfigurement" shall incorporate the descriptions and measurements of physical impairments and the corresponding percentages of impairments published in the American Medical Association (AMA) Guides to the Evaluation of Permanent Impairment (5th Edition).
(2) For purposes of this section, an employee's diminished future earning capacity shall be a numeric formula based on empirical data and findings that aggregate the average percentage of long-term loss of income resulting from each type of injury for similarly situated employees. The administrative director shall formulate the adjusted rating schedule based on empirical data and findings from the Evaluation of California's Permanent Disability Rating Schedule, Interim Report (December 2003), prepared by the RAND Institute for Civil Justice, and upon data from additional empirical studies.
(c) The Administrative Director shall amend the schedule for the determination of the percentage of permanent disability in accordance with this section at least once every five years. This schedule shall be available for public inspection and, without formal introduction in evidence, shall be prima facie evidence of the percentage of permanent disability to be attributed to each injury covered by the schedule.
(d) The schedule shall promote consistency, uniformity, and objectivity. The schedule and any amendment thereto or revision thereof shall apply prospectively and shall apply to and govern only those permanent disabilities that result from compensable injuries received or occurring on and after the effective date of the adoption of the schedule, amendment or revision, as the fact may be. For compensable claims arising before January 1, 2005, the schedule as revised pursuant to changes made in legislation enacted during the 2003-04 Regular and Extraordinary Sessions shall apply to the determination of permanent disabilities when there has been either no comprehensive medical-legal report or no report by a treating physician indicating the existence of permanent disability, or when the employer is not required to provide the notice required by Section 4061 to the injured worker.
(e) On or before January 1, 2005, the administrative director shall adopt regulations to implement the changes made to this section by the act that added this subdivision.
Pursuant to this authority, the Administrative Director has adopted this revised Schedule for Rating Permanent Disabilities.