Table:
|  |  | Year Ended December 31, |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Revenue | $576,523 | $537,891 | $481,985 |
| Foreign exchange effect on current period revenue using prior year rates | 7,077 | (5,291) | 5,865 |
| Constant currency revenue | $583,600 | $532,600 | $487,850 |
| Revenue growth | 7.2% | 11.6% | 13.9% |
| Constant currency revenue growth | 8.5% | 10.5% | 15.3% |
Paragraphs:
The following table presents a reconciliation of revenue to constant currency revenue (in thousands, except for revenue growth):
Total revenue growth declined to 7% in 2019 from 12% in 2018. Our growth rate can depend on a variety of factors, such as new customers, the size, volume, and complexity of our agreements with our customers, foreign currency movements, our ability to work with our customers to implement and deliver our products, our ability to upsell and renew our existing customers, the success of our alliance and partnership arrangements, and the expansion of our business through emerging markets. The decline in the growth rate of total revenue was driven by our strategic plan to transition away from one-time professional services and recommit our efforts to grow recurring revenue and free cash flows.
Question:
What was the change in Constant currency revenue between 2018 and 2019?