Between the date on which the district was formed and 90 days thereafter, and between those dates annually thereafter, the board shall file with the clerk of the board of supervisors an estimate of the sum required by the district to discharge all of its obligations:

(a) That are unpaid and matured at that date.

(b) That will mature during the next year.

(c) That it is probable will be incurred and mature during the next year.

(Amended by Stats. 1985, Ch. 717, Sec. 1. Effective September 18, 1985.)