Table:
|  | Years ended December 31 |  |  | 2019 vs 2018 | 2018 vs 2017 |
| --- | --- | --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 | % | % |
|  | (in thousands, except percentages) |  |  |  |  |
| Cost of revenues: |  |  |  |  |  |
| Cost of subscription solutions | $ 128,155 | $ 100,990 | $ 61,267 | 26.9 % | 64.8 % |
| Cost of merchant solutions | 584,375 | 375,972 | 231,784 | 55.4 % | 62.2 % |
| Total cost of revenues | $ 712,530 | $ 476,962 | $ 293,051 | 49.4 % | 62.8 % |
| Percentage of revenues: |  |  |  |  |  |
| Cost of subscription solutions | 8.1 % | 9.4 % | 9.1 % |  |  |
| Cost of merchant solutions | 37.0 % | 35.0 % | 34.4 % |  |  |
|  | 45.1 % | 44.4 % | 43.5 % |  |  |
Paragraphs:
Cost of Revenues
Cost of Subscription Solutions
Cost of subscription solutions increased $27.2 million, or 26.9%, for the year ended December 31, 2019 compared to the same period in 2018. The increase was primarily due to higher third-party infrastructure and hosting costs. The increase was also due to an increase in costs necessary to support a greater number of merchants using our platform, resulting in an increase in: credit card fees for processing merchant billings, employee-related costs, amortization of technology related to enhancing our platform, payments to third-party partners for the registration of domain names, and payments to third-party theme developers. As a percentage of revenues, costs of subscription solutions decreased from 9.4% in 2018 to 8.1% in 2019 due to a decrease in third-party infrastructure and hosting costs and employee-related costs as a percentage of revenue in 2019.
Cost of subscription solutions increased $39.7 million, or 64.8%, for the year ended December 31, 2018 compared to the same period in 2017. The increase was primarily due to higher third-party infrastructure and hosting costs as well as higher employee-related costs.
Cost of Merchant Solutions
Cost of merchant solutions increased $208.4 million, or 55.4%, for the year ended December 31, 2019 compared to the same period in 2018. The increase was primarily due to the increase in GMV facilitated through Shopify Payments, which resulted in higher payment processing and interchange fees. The increase was also due to higher amortization, largely related to the technology resulting from the 6RS acquisition, higher product costs associated with expanding our product offerings and higher credit card fees for processing merchant billings. Cost of merchant solutions as a percentage of revenues increased from 35.0% in 2018 to 37.0% in 2019, mainly as a result of Shopify Payments representing a larger percentage of total revenue.
Cost of merchant solutions increased $144.2 million, or 62.2%, for the year ended December 31, 2018 compared to the same period in 2017. The increase was primarily due to the increase in GMV facilitated through Shopify Payments, which resulted in payment processing fees, including interchange fees, increasing for the year ended December 31, 2018 as compared to the same period in 2017.
Question:
Which year had the highest total cost of revenues?
Answer: Because 712,530>476,962 , 712,530>293,051, the answer is: 2019.