Revenue
Recurring revenue consists of subscription-based software sales, support and maintenance revenue, recurring transactions revenue and recurring revenue from managed services solutions, such as outsourcing, private cloud hosting and revenue cycle management. Non-recurring revenue consists of perpetual software licenses sales, hardware resale and non-recurring transactions revenue, and project-based client services revenue.
Year Ended December 31, 2019 Compared with the Year Ended December 31, 2018
Recurring revenue decreased during the year ended December 31, 2019 compared to prior year due to known attrition within the EIS and other businesses partially offset with growth in subscription revenue. The sale of the OneContent business on April 2, 2018 also contributed to the decline in recurring revenue. The OneContent business was acquired as part of the EIS Business acquisition on October 2, 2017, and it contributed $13 million of recurring revenue during the first quarter of 2018, including $1 million of amortization of acquisition-related deferred revenue adjustments. Non-recurring revenue increased due to higher sales of perpetual software licenses for our acute solutions and hardware in 2019 compared to 2018, partially offset by lower client services revenue related to the timing of software activations.
The percentage of recurring and non-recurring revenue of our total revenue was 79% and 21%, respectively, during the year ended December 31, 2019 and 81% and 19%, respectively, during the year ended December 31, 2018.
Year Ended December 31, 2018 Compared with the Year Ended December 31, 2017
The increase in revenue for the year ended December 31, 2018 compared with the year ended December 31, 2017 was primarily driven by incremental revenue from the acquisitions of the EIS Business in the fourth quarter of 2017 and Practice Fusion in the first quarter of 2018. Total revenue includes the amortization of acquisition-related deferred revenue adjustments, which totaled $24 million and $29 million during the years ended December 31, 2018 and 2017, respectively. The growth in both recurring and non-recurring revenue for the year ended December 31, 2018 compared with the prior year was also largely driven by incremental revenue from the previously mentioned acquisitions.
The increase in revenue for the year ended December 31, 2018 compared with the year ended December 31, 2017 was primarily driven by incremental revenue from the acquisitions of the EIS Business in the fourth quarter of 2017 and Practice Fusion in the first quarter of 2018. Total revenue includes the amortization of acquisition-related deferred revenue adjustments, which totaled $24 million and $29 million during the years ended December 31, 2018 and 2017, respectively. The growth in both recurring and non-recurring revenue for the year ended December 31, 2018 compared with the prior year was also largely driven by incremental revenue from the previously mentioned acquisitions.
Table:
 |  |  | Year Ended December 31, |  | 
(In thousands) | 2019 | 2018 | 2017 | 2019 % Change from 2018 | 2018 % Change from 2017
Revenue: |  |  |  |  | 
Recurring revenue | $1,395,869 | $1,411,742 | $1,176,720 | (1.1%) | 20.0%
Non-recurring revenue | 375,808 | 338,220 | 320,988 | 11.1% | 5.4%
Total revenue | $1,771,677 | $1,749,962 | $1,497,708 | 1.2% | 16.8%


Question: What is the average Non-recurring revenue between 2017-2019?
Answer: 345005.33
Calculation: (375,808 + 338,220 + 320,988) / 3