Years Ended December 31,
Years Ended December 31,
2019
2018
Increase / (Decrease)
Net revenue
$713.3
$716.4
$(3.1)
Cost of revenue
572.3
600.4
(28.1)
Selling, general and administrative
79.8
66.9
12.9
Depreciation and amortization
15.5
7.4
8.1
Other operating (income) expense
0.6
(0.2)
0.8
Income from operations
45.1
$41.9
$3.2
segment results of operations in the company ' s consolidated financial statements other operating -income expense includes -i -gain loss on sale or disposal of assets -ii lease termination costs -iii asset impairment expense -iv accretion of asset retirement obligations and -v fcc reimbursements .
each table summarizes the results of operations of our operating segments and compares the amount of the change between the periods presented -in millions .
net revenue : net revenue from our construction segment for the year ended december 31 2019 decreased $ 3 .
1 million to $ 713 .
3 million from $ 716 .
4 million for the year ended december 31 2018 .
the decrease was primarily driven by lower revenues from our structural steel fabrication and erection business which had increased activity in the comparable period on certain large commercial construction projects that are now at or near completion in the current period .
this was largely offset by dbmg ’ s acquisition of graywolf which was acquired late in the fourth quarter of 2018 and from higher revenues from our construction modeling and detailing business as a result of an increase in project work .
cost of revenue : cost of revenue from our construction segment for the year ended december 31 2019 decreased $ 28 .
1 million to $ 572 .
3 million from $ 600 .
4 million for the year ended december 31 2018 .
the decrease was primarily driven by the timing of project activity on certain large commercial construction projects that are now at or near completion in the current period .
this was partially offset by costs associated with the construction modeling and detailing business as a result of an increase in project work and increases as a result of the acquisition of graywolf which was acquired late in the fourth quarter of 2018 .
selling general and administrative : selling general and administrative expenses from our construction segment for the year ended december 31 2019 increased $ 12 .
9 million to $ 79 .
8 million from $ 66 .
9 million for the year ended december 31 2018 .
the increase was primarily due to headcount-driven increases in salary and benefits and an increase in operating expenses as a result of the acquisition of graywolf which was acquired late in the fourth quarter of 2018 .
depreciation and amortization : depreciation and amortization from our construction segment for the year ended december 31 2019 increased $ 8 .
1 million to $ 15 .
5 million from $ 7 .
4 million for the year ended december 31 2018 .
the increase was due to amortization of intangibles obtained through the acquisition of graywolf and assets placed into service in 2019 .
other operating -income expense : other operating -income expense from our construction segment for the year ended december 31 2019 decreased by $ 0 .
8 million to a loss of $ 0 .
6 million from income of $ 0 .
2 million for the year ended december 31 2018 .
the change was primarily due to the gains and losses on the sale of land and assets in the comparable periods .

Question: What was the average cost of revenue for 2018 and 2019?
Answer: 586.35