Table:
|  | December 31, |  |
| --- | --- | --- |
|  | 2019 | 2018 |
| Cable-ships and submersibles | $ 246.5 | $ 251.1 |
| Equipment, furniture and fixtures, and software | 214.1 | 148.0 |
| Building and leasehold improvements | 48.9 | 47.3 |
| Land | 36.8 | 32.8 |
| Construction in progress | 14.3 | 12.9 |
| Plant and transportation equipment | 13.5 | 12.0 |
|  | 574.1 | 504.1 |
| Less: Accumulated depreciation | 168.3 | 127.8 |
| Total | $ 405.8 | $ 376.3 |
Paragraphs:
Property, plant and equipment consists of the following (in millions):
Depreciation expense was $52.3 million and $46.6 million for the years ended December 31, 2019 and 2018, respectively. These amounts included $9.1 million and $7.0 million of depreciation expense recognized within cost of revenue for the years ended December 31, 2019 and 2018, respectively.
As of December 31, 2019 and 2018 total net book value of equipment, cable-ships, and submersibles under capital leases consisted of $35.1 million and $40.0 million, respectively.
For the year ended December 31, 2018, our Energy segment recorded an impairment expense of $0.7 million, of which $0.4 million was due to station performance and $0.3 million was related to the abandonment of a station development project.
Question:
What is the increase / (decrease) in the Cable-ships and submersibles from 2018 to 2019?
Answer: 246.5 - 251.1 = -4.6