8. a. The weighted enrollment for each school district and county vocational school district shall be calculated as follows:
 
WENR = (PW x PENR) + (EW x EENR) + (MW x MENR) + (HW x HENR)
 
where
 
   PW is the applicable weight for kindergarten enrollment;
 
   EW is the weight for elementary enrollment;
 
   MW is the weight for middle school enrollment;
 
   HW is the weight for high school enrollment;
 
   PENR is the resident enrollment for kindergarten;
 
   EENR is the resident enrollment for grades 1 - 5;
 
   MENR is the resident enrollment for grades 6 - 8; and
 
   HENR is the resident enrollment for grades 9 - 12.
 
For the purposes of this section, ungraded pupils shall be counted in their age-equivalent grade.
 
   b.   The base cost for each school district shall be calculated as follows:
 
   BC = BPA x WENR; and
 
   the base cost for each county vocational school district shall be calculated as follows:
 
   BC = BPA x WENR x 1.31
 
where
 
   BPA is the base per pupil amount; and
 
   WENR is the weighted enrollment of the school district or county vocational school district.
 
   L.2007, c.260, s.8.