Table:
|  | Useful life (in years) | December 31, 2019 | December 31, 2018 |
| --- | --- | --- | --- |
| Equipment | 1-3 | $22,702 | $49,804 |
| Software | 1-3 | 726 | 4,088 |
| Furniture and fixtures | 1-3 | 459 | 967 |
| Leasehold improvements | 2-8 | 5,440 | 3,832 |
| Construction in progress |  | -- | 160 |
| Property and equipment, gross |  | 29,327 | 58,581 |
| Less: accumulated depreciation |  | (21,671) | (51,589) |
| Property and equipment, net |  | $7,656 | $7,262 |
Paragraphs:
Property and Equipment, Net
Property and equipment, net, consisted of the following (in thousands):
Depreciation expense on property and equipment was $5.0 million, $6.4 million and $7.1 million for the years
ended December 31, 2019, 2018 and 2017, respectively
Question:
What is the total depreciation expense on property and equipment from 2017 to 2019?
Answer: 5.0+6.4+7.1 = 18.5