(a) For each school district that meets, in the current or prior fiscal year, the conditions specified in Section 42281, 42282, or 42284 the county superintendent of schools shall compute, for each qualifying school in the district, an amount pursuant to this article.
(b) For each school district that is a countywide unified school district that had fewer than 2,501 units of average daily attendance in the 1990–91 fiscal year, the county superintendent of schools shall compute an amount pursuant to this article for those schools that meet the conditions specified in Sections 42283 and 42285 in the current or prior fiscal year. This subdivision is only applicable to those schools funded pursuant to this article in the 1990–91 fiscal year and, in subsequent years, if the school district has no more than 3,000 units of average daily attendance.
(c) For the 1998–99 fiscal year, average daily attendance reported pursuant to Section 41601 for the 1997–98 fiscal year, exclusive of average daily attendance for absences excused pursuant to subdivision (b) of Section 46010 as that subdivision read on July 1, 1996, shall be used for the purpose of determining whether school districts meet the conditions in Sections 42281, 42282, and 42284 for the prior fiscal year.