Ind. Code § 27-8-3-4
The trustees, directors, or managers, or the persons designated in the bylaws of the corporation, association, or society, subject to the provisions of this chapter, shall fix the fee rates and amounts of premiums, assessments, or periodical calls, and the time and manner of the payment thereof, and the risks to be assumed by such corporation, association, or society, and the duration thereof, and may change the same, from time to time, as the experience of the corporation, association, or society may require. An affidavit made by the person having charge of the mailing of notices of premiums, assessments, or periodical calls that any such notice was mailed to his last postoffice address, stating the date of mailing, shall be prima facie evidence thereof.
IC 27-8-3-4