On or after July 1, 2004, a company may elect to apply this part 5 to annuity contracts on a contract form-by-contract form basis. Otherwise, this part 5 shall apply to all annuity contracts created on or after July 1, 2005, and between July 1, 2004, and July 1, 2005, this part 5 as it existed on June 30, 2004, shall apply to all other annuity contracts.