In comparing year-over-year expenses, there is a significant change in Depreciation and Amortization expense. What caused this change?

12 Months Ended Dec. 31, 2019 Dec. 31, 2018 Dec. 31, 2017 S Change 2018 to 2019 % Change 2018 to 2019 $ Change 2017 to 2018% Change 2017 to 2018 $388,151 $27,489 $61,429 $577,426 $20,282 $40,043 $1,114,820 $376,676 $26,072 $52,088 $543,677 $0 $42,791) $1,041,304 $341,745 $23,038 $40,451 $499,625 10.22% 13.17% 28.77% 8.82% $36,438 $941,297 17.44% 10.62% 2.54% 114.52% 11.44% $168,833 $18,828 $579,139 $14,448 $781,248 $3,097 $100 $318,642 $165,821 $6,680 $479,400 $0 $651,901 Horizontal Analysis Consolidated Statements of Income - USD ($) in Thousands REVENUES: Royalty fees Initial franchise and relicensing fees Procurement services Marketing and reservation system Owned Hotels Other Total revenues OPERATING EXPENSES: Selling, general and administrative Depreciation and amortization Marketing and reservation system Owned Hotels Total operating expenses Impairment of goodwill Gain on sale of assets, net Operating income OTHER INCOME AND EXPENSES, NET: Interest expense Interest income Loss on extinguishment of debt Other (gain) loss Equity in net (income) loss of affiliates Total other income and expenses, net Income before income taxes Income taxes Net income Basic earnings per share: Basic earnings per share in dollars per share) Diluted earnings per share (in dollars per share) $170,027 $14,330 $534,266 $0 $718,623 -$4,289 $82 $318,474 10.23% $11,475.00 $1,417.00 $9,341.00 $33,749.00 $20,282.00 -$2,748.00 $73,516.00 $0.00 -$1,194.00 $4,498.00 $44,873.00 $14,448.00 $62,625.00 $1,192.00 $18.00 $168.00 $0.00 $899.00 -$2,544.00 $7,188.00 -$6,299.00 $4,253.00 $3,497.00 -$3,329.00 -$9,852.00 $6,523.00 $0.00 103.05% 105.43% 117.93% 106.21% 0.00% 93.58% 107.06% 0.00% 99.30% 131.39% 108.40% 0.00% 108.71% 72.21% 121.95% 100.05% 0.00% 101.96% 134.14% 0.00% -338.34% 179.90% 107.73% 98.78% 82.69% 103.01% 0.00% $34,931.00 $3,034.00 $11,637.00 $44,052.00 $0.00 $6,353.00 $100,007.00 $0.00 $4,206.00 $7,650.00 $54,866.00 $0.00 $66,722.00 -$4,289.00 -$175.00 $28,821.00 $0.00 $869.00 -$1,532.00 $0.00 $4,666.00 $777.00 $4,780.00 $24,041.00 $69,987.00 $94,028.00 $0.00 $257 $289,653 -68.09% 9.95% $45,039 -$5,920 1.93% 25.88% $0 $46,807 -$9,996 $7,188 -$4,862 $9,576 $48,713 $269,929 $47,051 $222,878 $45,908 -$7,452 $0 $1,437 $5,323 $45,216 $273,258 $56,903 $216,355 $3,229 $4,546 $40,436 $249,217 $126,890 $122,327 -144.50% 17.09% 11.82% 9.65% -55.16% 76.87% $4.00 $3.83 $2.16 $0.17 104.44% $1.67 77.31% $3.98 $3.80 $2.15 $0.18 104.74% $1.65 76.74%