pre_text: Item 6. Selected Financial Data. SELECTED CONSOLIDATED FINANCIAL DATA The following selected historical financial data should be read in conjunction with Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and our consolidated financial statements and the related notes appearing in Item 8, “Financial Statements and Supplementary Data,” of this Annual Report on Form 10-K to fully understand the factors that may affect the comparability of the information presented below. The selected consolidated financial data in this section are not intended to replace the consolidated financial statements and are qualified in their entirety by the consolidated financial statements and related notes included elsewhere in this Annual Report on Form 10-K. The following selected consolidated statements of operations data for the years ended December 31, 2019, 2018 and 2017, and the consolidated balance sheet data as of December 31, 2019 and 2018, have been derived from our audited consolidated financial statements included elsewhere in this Annual Report on Form 10-K. The consolidated statements of operations data for the years ended December 31, 2016 and 2015 and the consolidated balance sheet data as of December 31, 2017, 2016 and 2015 have been derived from our audited consolidated financial statements not included in this Annual Report on Form 10-K. The selected consolidated financial data for the year ended December 31, 2019 and as of December 31, 2019 reflects the adoption of ASU No. 2016-02, Leases (Topic 842). The selected consolidated financial data for the years ended December 31, 2019 and 2018 and as of December 31, 2019 and 2018 reflects the adoption of ASU No. 2014-09, Revenue from Contracts with Customers. See Notes 15 and 18 of the notes to consolidated financial statements for a summary of adjustments. The summary consolidated financial data for the years ended December 31, 2018, 2017, 2016 and 2015 and as of December 31, 2018, 2017, 2016 and 2015 does not reflect the adoption of ASU 2016-02. The summary consolidated financial data for the years ended December 31, 2017, 2016 and 2015 and as of December 31, 2017, 2016 and 2015 does not reflect the adoption of ASU 2014-09.
table: Year Ended December 31,
table: 2019 2018 2017 2016 2015
table: (in thousands, except shares and per share data)
table: Revenue $200,882 $147,094 $104,352 $76,846 $58,720
table: Cost of revenue(1) 63,535 46,810 31,503 23,767 19,789
table: Gross profit 137,347 100,284 72,849 53,079 38,931
table: Operating expenses:
table: Sales and marketing(1) 87,731 69,608 46,998 34,847 25,925
table: Research and development(1) 50,024 41,305 22,241 14,765 11,521
table: General and administrative(1) 46,820 31,462 22,895 14,293 12,272
table: Total operating expenses 184,575 142,375 92,134 63,905 49,718
table: Operating loss (47,228) (42,091) (19,285) (10,826) (10,787)
table: Other expenses, net (4,597) (4,628) (302) (484) (599)
table: Loss before income taxes (51,825) (46,719) (19,587) (11,310) (11,386)
table: (Provision for) benefit from income taxes (425) (796) (47) 24 562
table: Net loss $(52,250) $(47,515) $(19,634) $(11,286) $(10,824)
table: Net loss per share attributable to common shareholders - basic and diluted $(1.58) $(1.63) $(0.70) $(0.68) $(0.88)
table: Weighted average shares outstanding - basic and diluted 33,161,656 29,107,267 27,862,375 16,659,561 12,257,413
question: Analyse this data from a financial earnings document. What is the change in the Gross Profit from 2018 to 2019?