degree day average over the most recent 20-year period compared to the average in the consumption base level. (iii) Adjustments in consumption base level The Secretary shall make adjustments in the consumption base level to account for an increase or reduction in units, a change in fuel source, a change in resident controlled electricity consumption, or for other reasons. (iv) Savings All cost savings resulting from an election made by a small public housing agency under this subparagraph— (I) shall accrue to the small public housing agency