(1) The commission shall maintain and make available for public inspection and copying a current index which provides identifying information as to the following public records issued, adopted or promulgated after January 1, 1973:

(a) Statements of policy and interpretations of policy or statutes;

(b) Administrative staff manuals and instructions to staff that affect a member of the public;

(c) Planning policies and goals, and interim and final planning decisions;

(d) Factual staff reports and studies, factual consultant's reports and studies, scientific reports and studies, and any other factual information derived from tests, studies, reports, or surveys, whether conducted by public employees or others; and

(e) Correspondence, and materials referred to therein, by and with the agency relating to any regulatory, supervisory, or enforcement responsibilities of the agency, whereby the agency determines, opines upon, or is asked to determine or opine upon, the rights of the state, the public, a subdivision of state government, or of any private party.

(2) The current index maintained by the commission shall be available to all persons under the same rules and on the same conditions as are applied to public records available for inspection and/or copying.