The major components of our total CASM and our total CASM excluding special items and fuel for the years ended December 31, 2017 and 2016 are as follows (amounts may not recalculate due to rounding): Significant changes in the components of total CASM are as follows: 57 • Regional aircraft fuel and related taxes per ASM increased 23.2% primarily due to a 21.2% increase in the average price per gallon of fuel to $1.79 in 2017 from $1.48 in 2016 as well as a 2.8% increase in gallons of fuel consumed. • Depreciation and amortization per ASM increased 10.4% primarily due to our fleet renewal program, as we took delivery of 57 owned mainline aircraft in 2017. • Aircraft fuel and related taxes per ASM increased 19.5% primarily due to a 21.4% increase in the average price per gallon of fuel to $1.71 in 2017 from $1.41 in 2016, offset in part by a 0.5% decrease in gallons of fuel consumed. The decrease in fuel consumption was primarily driven by the operation of more fuel efficient aircraft during 2017 in connection with our fleet renewal program. • Salaries, wages and benefits per ASM increased 7.8% primarily due to mid-contract pay rate increases for pilots and flight attendants effective in the second quarter of 2017, as well as rate increases for maintenance and fleet service work groups, which became effective in the third quarter of 2016. • Maintenance, materials and repairs per ASM increased 5.6% as compared to 2016 primarily due to a contract change that accelerated the timing of certain maintenance expenses incurred. Certain flight equipment was transitioned to a new flight hour based contract (referred to as power by the hour) where expense is incurred and recognized based on actual hours flown. Previously, this flight equipment was covered by a time and materials based contract where expense is incurred and recognized as maintenance is performed. • Selling expenses per ASM increased 10.3% primarily due to higher commissions driven by the overall increase in revenues as well as an increase in flown premium tickets, which are subject to higher commissions. Year Ended December 31, Percent Increase (Decrease) 2017 2016 (In cents, except percentage changes) Total CASM: Aircraft fuel and related taxes 2.22 1.85 19.5 Salaries, wages and benefits 4.32 4.01 7.8 Maintenance, materials and repairs 0.71 0.67 5.6 Other rent and landing fees 0.65 0.65 0.8 Aircraft rent 0.43 0.44 (1.6) Selling expenses 0.53 0.48 10.3 Depreciation and amortization 0.62 0.56 10.4 Special items, net 0.26 0.26 0.6 Other 1.78 1.69 4.8 Regional expenses: Aircraft fuel and related taxes 0.50 0.41 23.2 Other 1.87 1.80 3.5 Total CASM 13.88 12.83 8.2 Special items, net: Special items, net (0.26) (0.26) (0.6) Regional operating special items, net (0.01 ) (0.01 ) 48.4 Aircraft fuel and related taxes Aircraft fuel and related taxes - mainline (2.22 ) (1.85 ) 19.5 Aircraft fuel and related taxes - regional (0.50) (0.41) 23.2 Total CASM, excluding special items and fuel 10.90 10.31 5.8