pre_text: GreenSky, Inc. NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued) (United States Dollars in thousands, except per share data, unless otherwise stated) Note 6. Property, Equipment and Software The following table shows depreciation and amortization expense, as well as recorded impairment losses related to abandoned capitalized software projects that are recorded within general and administrative expense in the Consolidated Statements of Operations. We determined that these software projects would not generate future cash flows through use or disposal to a third party and, as such, the fair value as of the respective reporting dates was $0.
table: Year Ended December 31,
table: 2019 2018 2017
table: Depreciation expense $2,540 $2,320 $2,149
table: Amortization expense 4,764 2,158 1,834
table: Impairment losses — 19 78
question: Analyse this data from a financial earnings document. What was the change in amortization expense between 2017 and 2018?