pre_text: Research and Development Research and development expenses in 2019 decreased by $4.6 million, or 21%, as compared to 2018. The decrease was primarily due to a reduction in the number of full-time research and development personnel, resulting in a decrease of $3.1 million in compensation expense and $0.6 million in allocated facilities and information technology costs as compared to 2018. We did not incur restructuring costs in 2019, as compared to 2018 when $0.1 million was incurred as part of the 2018 Restructuring Plan (refer to Note 4 of the accompanying consolidated financial statements). Finally, the decrease was further driven by lower professional fees of $0.6 million, as we reduced the number of research and development contractors as compared to 2018.
table: Years Ended December 31, Change
table: 2019 2018 $ %
table: (dollars in thousands)
table: Research and development $17,845 $22,450 $(4,605) (21)%
table: Percent of revenues, net 36% 38%
question: Analyse this data from a financial earnings document. What is the average research and development expense in 2018 and 2019?