Section 27-359. Capacity of exits

The  capacity  of  exits  and  access
  facilities shall be measured in units of width of twenty-two inches, and
  the number of persons per unit of  width  shall  be  determined  by  the
  occupancy  group classification and type of exit as listed in table 6-1.
  Fractions of a unit of width  less  than  twelve  inches  shall  not  be
  credited.  Where  twelve  inches  or  more are added to one or more full
  units  of  width,  one-half  unit  of  width  may  be  credited.   Where
  computations  of  total required width give fractional results, the next
  larger integral number of exit units or integral number  plus  one-half,
  shall  be  used. A fraction less than one-half may be neglected in cases
  where such fraction constitutes less than ten  per  cent  of  the  total
  required number of units. Notwithstanding any of the above computations,
  no  exit  or  access  facility  shall be narrower than the minimum width
  requirements specified in table 6-1, or elsewhere in this code.