Table:
|  | Year Ended December 31, |  | Change |  |
| --- | --- | --- | --- | --- |
|  | 2018 | 2017 | $ | % |
|  |  | (dollars in thousands) |  |  |
| General and administrative | $ 31,462 | $ 22,895 | $ 8,567 | 37.4% |
| % of revenue | 21% | 22% |  |  |
Paragraphs:
General and Administrative Expense
General and administrative expense increased by $8.6 million in 2018 compared to 2017. The increase was primarily due to a $3.7 million increase in employee-related costs, which includes stock-based compensation, associated with our increased headcount from 79 employees as of December 31, 2017 to 89 employees as of December 31, 2018. There was an additional increase of $2.8 million in depreciation and amortization, an increase of $1.5 million to support compliance as a public company, an increase of $0.4 million in software subscription cost and a $0.2 million increase in office related expenses to support the administrative team.
Question:
What is the change in the gross margin between 2017 and 2018?
Answer: 21 - 22 = -1