Any nonprofit organization which becomes subject to this act on or after January 1, 1972, may elect to become liable for payments in lieu of contributions for a period of not less than the remainder of the calendar year in which subjectivity occurs and the next two (2) succeeding calendar years by filing a written notice of its election with the Commission not later than thirty (30) days immediately following the date of the determination of such subjectivity.
Okla. Stat. tit. 40, § 3-804