All income remaining after allocation pursuant to Sections 12-6-2220 and 12-6-2230 is apportioned in accordance with Section 12-6-2252, or one of the special apportionment formulas provided in Sections 12-6-2290 through 12-6-2310.
S.C. Code § 12-6-2240
2007 Act No. 110, Section 55.E and 2007 Act No. 116, Section 60.B provide as follows:
"This section takes effect for tax years after 2010."