pre_text: Gross Profit Year Ended December 31, 2019 Compared with the Year Ended December 31, 2018 Gross profit and margin decreased during the year ended December 31, 2019 compared to prior year primarily due to an increase in hosting migration costs, higher amortization of software development, recognition of previously deferred costs and the sale of OneContent business on April 2, 2018, which carried a higher gross margin compared with our other businesses. These were partially offset with an increase in organic sales for Veradigm and our acute solutions in 2019. Year Ended December 31, 2018 Compared with the Year Ended December 31, 2017 Gross profit increased during the year ended December 31, 2018 compared with the year ended December 31, 2017 primarily due to acquisitions. From a revenue mix perspective, gross profit associated with our recurring revenue streams, which include the delivery of recurring subscription-based software sales, support and maintenance, and recurring client services improved as we continued to expand our customer base for these services, particularly those related to outsourcing and revenue cycle management. Gross profit associated with our non-recurring software delivery, support and maintenance revenue stream decreased primarily due to fewer perpetual software license sales of our acute and population health management solutions. Gross profit associated with our non-recurring client services revenue stream, which includes non-recurring project-based client services, decreased primarily driven by higher internal personnel costs, including those related to incremental resources from recent acquisitions. Gross margin decreased primarily due to lower sales of higher margin perpetual software licenses and higher amortization of software development and acquisition-related assets driven by additional amortization expense associated with intangible assets acquired as part of recent acquisitions.
table: Year Ended December 31,
table: (In thousands) 2019 2018 2017 2019 % Change from 2018 2018 % Change from 2017
table: Total cost of revenue $ 1,058,097 $ 1,025,419 $ 864,909 3.2% 18.6%
table: Gross profit $ 713,580 $ 724,543 $ 632,799 (1.5%) 14.5%
table: Gross margin % 40.3% 41.4% 42.3%
question: Analyse this data from a financial earnings document. What is the average gross profit between 2017-2019?