Table:
|  |  |  | For the Years Ended December 31, |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
|  | 2019 |  | 2018 |  | 2017 |  |
|  | Amount | % of Revenue | Amount | % of Revenue | Amount | % of Revenue |
|  |  |  | (In millions, except percentages) |  |  |  |
| Revenues | $13.2 | 100% | $82.3 | 100% | $50.5 | 100% |
| Cost of revenues | 1.9 | 14% | 15.3 | 19% | 6.0 | 12% |
| Gross profit | 11.3 | 86% | 67.0 | 81% | 44.5 | 88% |
| Operating expenses: |  |  |  |  |  |  |
| Selling, general and administrative (1) | 31.7 | 240% | 32.2 | 39% | 28.6 | 57% |
| Research and development | 2.0 | 15% | 2.1 | 2% | 1.5 | 3% |
| Total operating expenses | 33.7 | 225% | 34.3 | 41% | 30.1 | 60% |
| Other income (expense) | (0.3) | (2)% | (4.0) | (5)% | 2.2 | 4% |
| Income (loss) before income taxes | (22.7) | (172%) | 28.7 | 35% | 16.6 | 33% |
| Income tax provision (benefit) | (6.2) | (47%) | 8.0 | 10% | (6.2) | (12)% |
| Net income (loss) | $(16.5) | (125)% | $20.7 | 25% | $22.8 | 45% |
| (1) Includes stock based compensation | $1.0 | 8% | $1.6 | 2% | $0.8 | 2% |
Paragraphs:
Results of Operations
We operate a cybersecurity business, focused on licensing and enforcement, providing advisory services, developing mobile security applications, and investing in emerging cybersecurity technologies and intellectual property. The following table summarizes our results of operations for the periods presented and as a percentage of our total revenue for those periods based on our consolidated statement of operations data. The year to year comparison of results of operations is not necessarily indicative of results of operations for future periods.
Question:
What is the percentage change in cost of revenue between 2017 and 2018?
Answer: (15.3-6)/6  = 155