On or before September 30, 2018, and by September thirtieth of each year thereafter, the Revenue and Fiscal Affairs Office shall estimate the number of taxpayers expected to claim the credit for the current tax year and the total amount expected to be claimed. In the event that the Revenue and Fiscal Affairs Office estimates that the total amount of credits claimed will exceed the maximum amount of aggregate credit allowed pursuant to this item, the Revenue and Fiscal Affairs Office shall certify to the Department of Revenue a pro rata adjustment to the credit otherwise provided.
S.C. Code § 12-6-3780
2017 Act No. 40, Section 15.C, provides as follows:
"This SECTION takes effect upon approval by the Governor, and subsection A first applies to tax years beginning after 2017."