This is the Congressional Budget Office Cost Estimate as ordered reported by the Senate Committee on Commerce, Science, and Transportation on July 22, 2020. From the Document: "S. 4162 would temporarily modify the apportionment formula for Airport Improvement Program (AIP) grants, which provide funding to airport sponsors for capital improvement projects related to airport safety, capacity, and security. In general, under current law, each airport's annual apportionment is based on the number of passengers at that facility during the previous calendar year. For 2022 and 2023, the bill would direct the Federal Aviation Administration (FAA) to calculate AIP apportionments based on the number of passengers at each airport in 2018, 2019, or the full calendar year prior to the current fiscal year, whichever would result in the highest amount."
Congressional Budget Office: https://www.cbo.gov/