(1) For school fiscal years prior to school fiscal year 2017-18:

(a) The department shall calculate an averaging adjustment for districts if the basic funding per formula student is less than the averaging adjustment threshold and the general fund levy for the school fiscal year immediately preceding the school fiscal year for which aid is being calculated was at least one dollar per one hundred dollars of taxable valuation. For the calculation of aid for school fiscal years prior to school fiscal year 2018-19, the general fund levy for school districts that are members of a learning community for purposes of this section includes both the common general fund levy and the school district general fund levy authorized pursuant to subdivisions (2)(b) and (2)(c) of section 77-3442. The averaging adjustment shall equal the district's formula students multiplied by the percentage specified in this subsection for such district of the difference between the averaging adjustment threshold minus such district's basic funding per formula student;

(b) The averaging adjustment threshold shall equal the aggregate basic funding for all districts with nine hundred or more formula students divided by the aggregate formula students for all districts with nine hundred or more formula students for the school fiscal year for which aid is being calculated; and

(c) The percentage to be used in the calculation of an averaging adjustment shall be based on the general fund levy for the school fiscal year immediately preceding the school fiscal year for which aid is being calculated and shall be as follows:

(i) If such levy was at least one dollar per one hundred dollars of taxable valuation but less than one dollar and one cent per one hundred dollars of taxable valuation, the percentage shall be fifty percent;

(ii) If such levy was at least one dollar and one cent per one hundred dollars of taxable valuation but less than one dollar and two cents per one hundred dollars of taxable valuation, the percentage shall be sixty percent;

(iii) If such levy was at least one dollar and two cents per one hundred dollars of taxable valuation but less than one dollar and three cents per one hundred dollars of taxable valuation, the percentage shall be seventy percent;

(iv) If such levy was at least one dollar and three cents per one hundred dollars of taxable valuation but less than one dollar and four cents per one hundred dollars of taxable valuation, the percentage shall be eighty percent; and

(v) If such levy was at least one dollar and four cents per one hundred dollars of taxable valuation, the percentage shall be ninety percent.

(2) For school fiscal year 2017-18 and each school fiscal year thereafter, the department shall calculate an averaging adjustment for districts with at least nine hundred formula students if the basic funding per formula student is less than the averaging adjustment threshold. The averaging adjustment shall equal the district's formula students multiplied by ninety percent of the difference of the averaging adjustment threshold minus such district's basic funding per formula student. The averaging adjustment threshold shall equal the aggregate basic funding for all districts with nine hundred or more formula students divided by the aggregate formula students for all districts with nine hundred or more formula students for the school fiscal year for which aid is being calculated.