Joint collective bargaining agreements (JCBAs) have been reached with post-Merger employee groups, except for contracts with the TWU-IAM Association which represents the maintenance, fleet service, stock clerks, maintenance control technicians and maintenance training instructors whose contracts became amendable in the third quarter of 2018. Negotiations designed to reach JCBAs involving all of these workgroups continue. Additionally, the post-Merger JCBAs covering our pilots and flight attendants, while not yet amendable, provide the unions with the right to elect to commence negotiations for new collective bargaining agreements in advance of each JCBA’s amendable date. Both of the unions have exercised these rights and negotiations are underway for new agreements. Among our wholly-owned regional subsidiaries, the PSA flight attendants have an agreement that is now amendable and are engaged in traditional RLA negotiations. In January 2019, the Envoy passenger service employees reached a tentative seven-year labor agreement subject to membership ratification. For more discussion, see Part I, Item 1A. Risk Factors – “ Union disputes, employee strikes and other labor-related disruptions, or our inability to otherwise maintain labor costs at competitive levels may adversely affect our operations and financial performance .” Our operations and financial results are significantly affected by the availability and price of jet fuel, which is our second largest expense. Based on our 2019 forecasted mainline and regional fuel consumption, we estimate that a one cent per gallon increase in aviation fuel price would increase our 2019 annual fuel expense by $45 million. The following table shows annual aircraft fuel consumption and costs, including taxes, for our mainline and regional operations for 2018, 2017 and 2016 (gallons and aircraft fuel expense in millions). As of December 31, 2018, we did not have any fuel hedging contracts outstanding to hedge our fuel consumption. As such, and assuming we do not enter into any future transactions to hedge our fuel consumption, we will continue to be fully Aircraft Fuel Union Class or Craft Employees  (1) Contract Amendable Date Piedmont: ALPA Pilots 630 2024 AFA Flight Attendants 300 2019 International Brotherhood of Teamsters (IBT) Mechanics 375 2021 IBT Stock Clerks 60 2021 CWA  Fleet and Passenger Service 3,650 2023 IBT Dispatchers 30 2019 ALPA  Flight Crew Training Instructors 40 2024 PSA: ALPA Pilots 1,650 2023 AFA Flight Attendants 1,250 2017 International Association of Machinists & Aerospace Workers (IAM) Mechanics 470 2022 TWU Dispatchers 60 2022 Year Gallons Average Price per Gallon Aircraft Fuel Expense Percent of Total Operating Expenses 2018 4,447 $2.23 $9,896 23.6% 2017 4,352 1.73 7,510 19.6% 2016 4,347 1.42 6,180 17.6% 10 $^{(1)}$  Approximate number of active full-time equivalent employees as of December 31, 2018.