Annual purchase commitments under various contracts as of May 31, 2015 were as follows (in millions):

		Aircraft and
		Aircraft Related		Other⁽¹⁾		Total

2016		$	1,255	$	1,060	$	2,315
2017			1,024		235		1,259
2018			1,399		128		1,527
2019			1,017		69		1,086
2020			662		22		684
Thereafter			3,786		89		3,875
Total		$	9,143	$	1,603	$	10,746

⁽¹⁾	Primarily equipment, advertising contracts and in 2016, approximately $500 million of estimated required quarterly contributions to our U.S. Pension Plans.

The amounts reflected in the table above for purchase commitments represent noncancelable agreements to purchase goods or services. As of May 31, 2015, our obligation to purchase three Boeing 767-300 Freighter (“B767F”) aircraft and nine Boeing 777 Freighter (“B777F”) aircraft is conditioned upon there being no event that causes FedEx Express or its employees not to be covered by the Railway Labor Act of 1926, as amended. Commitments to purchase aircraft in passenger configuration do not include the attendant costs to modify these aircraft for cargo transport unless we have entered into noncancelable commitments to modify such aircraft. Open purchase orders that are cancelable are not considered unconditional purchase obligations for financial reporting purposes and are not included in the table above.

We have several aircraft modernization programs underway that are supported by the purchase of B777F, B767F and B757 aircraft. These aircraft are significantly more fuel-efficient per unit than the aircraft types previously utilized, and these expenditures are necessary to achieve significant long-term operating savings and to replace older aircraft. Our ability to delay the timing of these aircraft-related expenditures is limited without incurring significant costs to modify existing purchase agreements.

During September 2014, FedEx Express entered into an agreement to purchase four additional B767F aircraft, the delivery of which will begin in 2017 and continue through 2019.

We had $472 million in deposits and progress payments as of May 31, 2015 on aircraft purchases and other planned aircraft-related transactions. These deposits are classified in the “Other assets” caption of our consolidated balance sheets. Aircraft and aircraft-related contracts are subject to price escalations. The following table is a summary of the key aircraft we are committed to purchase as of May 31, 2015, with the year of expected delivery:

	B767F	B777F	Total

2016	11	2	13
2017	12	-	12
2018	11	2	13
2019	6	2	8
2020	-	3	3
Thereafter	-	9	9
Total	40	18	58