(820 ILCS 405/1503.1) (from Ch. 48, par. 573.1)
    Sec. 1503.1. Benefit ratio. A. For calendar year 1991:
    1. For each employer who has incurred liability for the payment of contributions within each of the three calendar years immediately preceding calendar year 1991, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 12 consecutive calendar month period ending on June 30, 1990, multiplied by the benefit conversion factor, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 12 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    2. For each employer who has incurred liability for the payment of contributions within each of the four calendar years immediately preceding calendar year 1991, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 12 consecutive calendar month period ending on June 30, 1990, multiplied by the benefit conversion factor, and his benefit wages for the 12 consecutive calendar month period ending on June 30, 1989, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 24 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    3. For each employer who has incurred liability for the payment of contributions within each of the five calendar years immediately preceding calendar year 1991, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 12 consecutive calendar month period ending on June 30, 1990, multiplied by the benefit conversion factor, and his benefit wages for the 24 consecutive calendar month period ending on June 30, 1989, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 36 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    B. For calendar year 1992:
    1. For each employer who has incurred liability for the payment of contributions within each of the three calendar years immediately preceding calendar year 1992, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 12 consecutive calendar month period ending on June 30, 1991, multiplied by the benefit conversion factor, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 12 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    2. For each employer who has incurred liability for the payment of contributions within each of the four calendar years immediately preceding calendar year 1992, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 24 consecutive calendar month period ending on June 30, 1991, multiplied by the benefit conversion factor, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 24 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    3. For each employer who has incurred liability for the payment of contributions within each of the five calendar years immediately preceding calendar year 1992, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 24 consecutive calendar month period ending on June 30, 1991, multiplied by the benefit conversion factor, and his benefit wages for the 12 consecutive calendar month period ending on June 30, 1989, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 36 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    C. For calendar year 1993 and each calendar year thereafter:
    1. For each employer who has incurred liability for the payment of contributions within each of the three calendar years immediately preceding the calendar year for which a rate is being determined, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 12 consecutive calendar month period ending on the June 30 immediately preceding that calendar year, multiplied by the benefit conversion factor, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 12 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    2. For each employer who has incurred liability for the payment of contributions within each of the four calendar years immediately preceding the calendar year for which a rate is being determined, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 24 consecutive calendar month period ending on the June 30 immediately preceding that calendar year, multiplied by the benefit conversion factor, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 24 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
    3. For each employer who has incurred liability for the payment of contributions within each of the five calendar years immediately preceding the calendar year for which a rate is being determined, the benefit ratio shall be a percentage equal to the total of his benefit charges for the 36 consecutive calendar month period ending on the June 30 immediately preceding that calendar year, multiplied by the benefit conversion factor, divided by his total wages for insured work subject to the payment of contributions under Sections 234, 235, and 245 of this Act for the same 36 month period, provided, however, that such wages shall not include either those wages estimated by the Director prior to the issuance of a Determination and Assessment or those wages estimated as a result of an audit because of an employer's failure to report wages.
(Source: P.A. 85-956.)