Cal. INS § 11552

As used in this article, the term “earned premium,” means the amount remaining of the gross premiums charged on all policies written, including all determined excess and additional premiums, after deducting the aggregate of: (a) Return premiums other than premiums returned to policyholders as dividends. (b) Reinsurance premiums and premiums on policies canceled. (c) Unearned premiums on policies in force.