please answer 9

The 2016 income statement and balance sheet (excerpts) for BNSF Railway are below.

BNSF Railway

Consolidated Statements of Income

Year ended December 31,	2016	2015	2014
(In millions)
Revenues	$19,829	$21,967	$23,239
Operating expenses:
Compensation and benefits	4,769	5,043	5,023
Purchased services	2,418	2,546	2,592
Depreciation and amortization	2,128	2,001	2,123
Fuel	1,934	2,656	4,478
Equipment rents	766	801	867
Materials and other	1,129	1,196	1,143
Total operating expenses	13,144	14,243	16,226
Operating income	6,685	7,724	7,013
Interest expense	992	928	833
Other expense, net	0	21	11
Income before income taxes	5,693	6,775	6,169
Income tax expense	2,124	2,527	2,300
Net income	$ 3,569	$ 4,248	$ 3,869

BNSF Railway

Consolidated Balance Sheets

December 31,	2016	2015
(in millions)
Current assets
Cash and cash equivalents	$ 3,218	$ 2,329
Accounts receivable, net	1,272	1,198
Materials and supplies	825	829
Current portion of deferred income taxes	0	245
Other current assets	235	337
Total current assets	5,550	4,938

Property and equipment, net of accumulated depreciation of $6,130 and $4,845, respectively	61,250	59,510
Goodwill	14,845	14,845
Intangible assets, net	430	468
Other assets	2,047	1,942
Total assets	$84,122	$81,703

The footnotes to the financial statements included the following:

Property and equipment, net (in millions), and the corresponding ranges of estimated useful lives were as follows:

December 31,	2016		2015		2016 Range of Estimated Useful Life
Land for transportation purposes	$ 6,063		$ 6,037		—
Track structure	22,287		21,200		15-50 years
Other roadway	25,990		24,767		7-100 years
Locomotives	8,338		7,794		7-35 years
Freight cars and other equipment	2,755		2,629		8-40 years
Computer hardware, software, and other	982		897		6-9 years
Construction in progress	965		1,031		—
Total cost	67,380		64,355
Less accumulated depreciation and amortization	(6,130	)	(4,845	)
Property and equipment, net	$61,250		$59,510

Required:

a.	What proportion of total assets, does BNSF hold as property and equipment in 2016 and 2015? Does this surprise you?
b.	Compute property and equipment turnover for 2016 and 2015. Property and equipment, net for 2014 was $55,806 million. Explain this ratio.
c.	By what percentage are the assets ‘used up’ at year-end 2016? What implication does this ratio have for future cash flows at BNSF?
d.	Estimate the useful life on average for the BNSF depreciable assets at year-end 2016. Which of the assets listed in the footnote explain this estimated useful life?