pre_text: General and Administrative Expense General and administrative expense increased by $15.4 million in 2019 compared to 2018. The increase was primarily due to a $9.8 million increase in employee-related costs, which includes stock-based compensation, associated with our increased headcount from 89 employees as of December 31, 2018 to 113 employees as of December 31, 2019. There was an additional increase of $3.7 million in depreciation and amortization, $0.8 million to support compliance as a public company, a $0.6 million increase in office related expenses to support the administrative team, and an increase of $0.2 million in software subscription costs.
table: Year Ended December 31, Change
table: 2019 2018 $ %
table: (dollars in thousands)
table: General and administrative $ 46,820 $ 31,462 $ 15,358 48.8%
table: % of revenue 23% 21%
question: Analyse this data from a financial earnings document. What was the average General and administrative expense for 2018 and 2019?