Add together the percentages determined in accordance with sub-paragraphs (a), (b) and (c) of Section 181.05 or such of the aforesaid percentages as are applicable to the particular taxpayer and divide the total so obtained by the number of percentages used deriving said total in order to obtain the business allocation percentage referred to in Section 181.05. A factor is applicable even though it may be allocable entirely in or outside the City.
(1969 Code 92.07)