pre_text: 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.
table: December 31,
table: 2019 2018
table: Cable-ships and submersibles $ 246.5 $ 251.1
table: Equipment, furniture and fixtures, and software 214.1 148.0
table: Building and leasehold improvements 48.9 47.3
table: Land 36.8 32.8
table: Construction in progress 14.3 12.9
table: Plant and transportation equipment 13.5 12.0
table: 574.1 504.1
table: Less: Accumulated depreciation 168.3 127.8
table: Total $ 405.8 $ 376.3
question: Analyse this data from a financial earnings document. What is the average Building and leasehold improvements?