All totaled, our first quarter adjusted operating income increased 56% year-over-year primarily due to international priority volume growth of 31%, a surge in demand for U.S. residential delivery, yield improvement at FedEx Ground and FedEx Freight, a $130 million benefit from an additional operating day, a $65 million benefit from a reduction in aviation excise taxes provided by the Cares Act and a better alignment of our expenses, especially at FedEx Freight.
subsidiary: FedEx, FedEx Ground; parent_organization: FedEx Ground, FedEx