(a) The department shall determine each eligible employer's contribution rate by the procedures set out in AS 23.20.280 - 23.20.310. The department shall put the employer's quarterly payrolls in chronological order beginning with the first calendar quarter in the qualifying period and ending with the last calendar quarter in the period. If an employer's payroll in a calendar quarter is less than the payroll in the preceding quarter in the qualifying period, the quarterly decline quotient shall be computed to at least nine decimal places by dividing the amount of the decline by the amount of the payroll in the preceding calendar quarter.
(b) For the purpose of computing quarterly decline quotients, the department may, by regulation, prescribe (1) the manner in which wages paid in the form of annual bonuses or other lump-sum payments for service performed over a period of more than three months are apportioned among the calendar quarters of the calendar year in which the service was performed; and (2) the method for making adjustments in quarterly payrolls to eliminate the effect upon quarterly decline quotients resulting from unemployment which would not be compensable by reason of the labor dispute provision of AS 23.20.383.
(c) The department shall determine the sum of each eligible employer's decline quotients and shall weight the sum by adding to it 1.000000000 for each quarter in the employer's qualifying period in which the employer has no payroll, which quarter immediately follows a quarter in which the employer has no payroll. Each eligible employer's average quarterly decline quotient shall be computed to the ninth decimal place by dividing the sum of the quarterly decline quotients for the employer, weighted when required by this section, by the number of quarters in the employer's qualifying period less one.