Table:
|  |  | Year Ended December 31, |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Stock-based compensation expense data: |  |  |  |
| Sales and marketing | $2,075 | $1,196 | $561 |
| General and administrative | 6,474 | 4,901 | 2,638 |
| Research and development | 12,054 | 7,332 | 4,214 |
| Total stock-based compensation expense | $20,603 | $13,429 | $7,413 |
Paragraphs:
Results of Operations
(2) Operating expenses include stock-based compensation expense as follows (in thousands):
Question:
What years does the table provide information for total stock-based compensation expense?
Answer: 2019, 2018, 2017