Table:
|  | Years ended December 31, |  |  | 2019 vs 2018 | 2018 vs 2017 |
| --- | --- | --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 | % Change | % Change |
|  | (in thousands, except percentages) |  |  |  |  |
| General and administrative | $ 178,934 | $ 107,444 | $ 67,719 | 66.5 % | 58.7 % |
| Percentage of total revenues | 11.3 % | 10.0 % | 10.1 % |  |  |
Paragraphs:
General and Administrative
General and administrative expenses increased $71.5 million, or 66.5%, for the year ended December 31, 2019 compared to the same period in 2018, due to an increase of $28.7 million in employee-related costs ($12.2 million of which related to stock-based compensation and related payroll taxes), a $14.9 million increase in finance costs, which include an estimated net liability for non-recurring HST payable to the Government of Canada in the amount of $8.1 million related to 2019 and prior years, sales and use and other value added taxes, insurance, and bank fees, a $9.0 million increase in Shopify Payments losses driven by increased GMV processed through Shopify Payments, a $8.6 million increase in losses and insurance related to Shopify Capital driven by an expansion of our Capital offerings and programs, a $6.9 million increase in professional services fees for legal and tax services, including those related to our international expansion and the growth of our business, a $1.8 million increase in computer and software costs, and a $1.6 million increase in general bad debt expense. General and administrative expenses increased $71.5 million, or 66.5%, for the year ended December 31, 2019 compared to the same period in 2018, due to an increase of $28.7 million in employee-related costs ($12.2 million of which related to stock-based compensation and related payroll taxes), a $14.9 million increase in finance costs, which include an estimated net liability for non-recurring HST payable to the Government of Canada in the amount of $8.1 million related to 2019 and prior years, sales and use and other value added taxes, insurance, and bank fees, a $9.0 million increase in Shopify Payments losses driven by increased GMV processed through Shopify Payments, a $8.6 million increase in losses and insurance related to Shopify Capital driven by an expansion of our Capital offerings and programs, a $6.9 million increase in professional services fees for legal and tax services, including those related to our international expansion and the growth of our business, a $1.8 million increase in computer and software costs, and a $1.6 million increase in general bad debt expense.
General and administrative expenses increased $39.7 million, or 58.7%, for the year ended December 31, 2018 compared to the same period in 2017, due to an increase of $30.3 million in employee-related costs, a $4.5 million increase in professional services fees for legal and tax services, a $4.0 million increase in finance costs, which includes insurance, sales and use and other value added taxes, and a $1.7 million increase in computer and software costs.
Question:
What is the average general and administrative expenses for 2017 and 2018?