The following tables present our financial information by segment: Year Ended December 31, 2019 (in $000s) ERS PTA Total Rental revenue (1) $ 182,720 $ 15,276 $ 197,996 Sales of rental equipment 23,767  23,767 Sales of new equipment 10,308  10,308 Parts sales and services  31,964 31,964 Total revenue 216,795 47,240 264,035 Cost of revenue 76,573 30,346 106,919 Depreciation of rental equipment 66,228 4,340 70,568 Gross profit $ 73,994 $ 12,554 $ 86,548 Year Ended December 31, 2018 (in $000s) ERS PTA Total Rental revenue (1)(2) $ 173,267 $ 11,296 $ 184,563 Sales of rental equipment 26,019  26,019 Sales of new equipment 18,349  18,349 Parts sales and services  17,366 17,366 Total revenue 217,635 28,662 246,297 Cost of revenue 84,509 16,077 100,586 Depreciation of rental equipment 60,436 3,657 64,093 Gross profit $ 72,690 $ 8,928 $ 81,618 Year Ended December 31, 2017 (in $000s) ERS PTA Total Rental revenue (1)(2) $ 152,993 $ 7,895 $ 160,888 Sales of rental equipment 17,162  17,162 Sales of new equipment 10,093  10,093 Parts sales and services  15,624 15,624 Total revenue 180,248 23,519 203,767 Cost of revenue 69,463 14,686 84,149 Depreciation of rental equipment 58,878 2,995 61,873 Gross profit $ 51,907 $ 5,838 $ 57,745 (1) As discussed in Note 2, Summary of Significant Accounting Policies , rental revenue is primarily comprised of revenues from rental agreements and freight charges billed to customers as well as charges to customers for damaged equipment. Effective in 2019, $2.9 million of billings to customers for damages are classified in rental revenue, given that the amounts are directly related to the Companys rental arrangements with its customers. Amounts for damages in comparable prior periods have been reclassified to rental revenue from parts sales and services ( $3.2 million and $2.6 million for the years ended December 31, 2018 and 2017, respectively). (2) Amounts for equipment rental revenue of $0.5 million and $0.9 million for the years ended December 31, 2018 and 2017, respectively, previously reported in the PTA segment as rental revenue have been reclassified to the ERS segment to align the reportable segment information to the information our CODM began receiving on a regular basis in 2019.