Beginning with the 2018 calendar year, each of the average monthly charges calculated in subparagraphs (A) through (C) of this paragraph (1) shall be equal to the average of each such charge applied over a period that commences with the calendar year ending December 31, 2017 and ends with the most recently completed calendar year prior to the calculation or calculations required by this Section.
Beginning with the 2018 calendar year, each of the values identified in subparagraphs (A) and (B) of this paragraph (2) shall be equal to the average of each such value during a period that commences with the calendar year ending December 31, 2017 and ends with the most recently completed calendar year prior to the calculation or calculations required by this Section.
If the actual or projected average monthly increase for residential retail customers of electric utility that serves more than 3 million retail customers in the State exceeds $0.25, or the actual or projected average monthly increase for residential retail customers of an electric utility that serves more than 500,000 but less than 3 million retail customers in the State exceeds $0.35, then the applicable utility shall comply with the provisions of paragraphs (2) through (4) of this subsection (c), as applicable.
220 ILCS 5/16-108.15