pre_text: The following is selected financial data for our reportable segments (in thousands): ACI On Premise Segment Adjusted EBITDA decreased $2.6 million for the year ended December 31, 2019, compared to the same period in 2018, primarily due to a $5.2 million increase in cash operating expense, partially offset by a $2.6 million increase in revenue. ACI On Demand Segment Adjusted EBITDA increased $54.5 million for the year ended December 31, 2019, compared to the same period in 2018, of which $46.4 million was due to the acquisition of Speedpay. Excluding the impact of the acquisition of Speedpay, ACI On Demand Segment Adjusted EBITDA increased $8.1 million, primarily due to a $18.3 million increase in revenue, partially offset by a $10.2 million increase in cash operating expense.
table: Years Ended December 31,
table: 2019 2018
table: Revenues
table: ACI On Premise $579,334 $576,755
table: ACI On Demand 678,960 433,025
table: Total revenue $ 1,258,294 $ 1,009,780
table: Segment Adjusted EBITDA
table: ACI On Premise $321,305 $323,902
table: ACI On Demand 66,501 12,015
table: Depreciation and amortization (122,569 ) (97,350 )
table: Stock-based compensation expense (36,763 ) (20,360 )
table: Corporate and unallocated expenses (104,718 ) (92,296 )
table: Interest, net (52,066 ) (30,388 )
table: Other, net 520 (3,724 )
table: Income before income taxes $ 72,210 $ 91,799
table: Depreciation and amortization
table: ACI On Premise $ 11,992 $ 11,634
table: ACI On Demand 34,395 31,541
table: Corporate 76,182 54,175
table: Total depreciation and amortization $ 122,569 $ 97,350
table: Stock-based compensation expense
table: ACI On Premise $ 7,651 $ 4,348
table: ACI On Demand 7,995 4,338
table: Corporate and other 21,117 11,674
table: Total stock-based compensation expense $ 36,763 $ 20,360
question: Analyse this data from a financial earnings document. What was the change in Corporate depreciation and amortization between 2018 and 2019?