(In millions, except per share amounts)
Year Ended June 30,
2019 (a)
2018
2017 (d)(e)
2016 (d)
2015
Revenue
$ 125,843
$ 110,360
$ 96,571
$ 91,154
$ 93,580
Gross margin
82,933
72,007
62,310
58,374
60,542
Operating income
42,959
35,058
29,025 (f)
26,078 (g)
18,161(h)
Net income
39,240(b)
16,571(c)
25,489 (f)
20,539 (g)
12,193(h)
Diluted earnings per share
5.06 (b)
2.13(c)
3.25 (f)
2.56 (g)
1.48(h)
Cash dividends declared per share
1.84
1.68
1.56
1.44
1.24
Cash, cash equivalents, and short-term
investments
133,819
133,768
132,981
113,240
96,526
Total assets
286,556
258,848
250,312
202,897
174,303
Long-term obligations
114,806
117,642
106,856
66,705
44,574
Stockholders’ equity
102,330
82,718
87,711
83,090
80,083

text: (a) GitHub has been included in our consolidated results of operations starting on the October 25, 2018 acquisition date.
text: (b) Includes a $2.6 billion net income tax benefit related to intangible property transfers and a $157 million net charge related to the enactment of the Tax Cuts and Jobs Act (“TCJA”), which together increased net income and diluted earnings per share (“EPS”) by $2.4 billion and $0.31, respectively. Refer to Note 12 – Income Taxes of the Notes to Financial Statements for further discussion.
text: (c) Includes a $13.7 billion net charge related to the enactment of the TCJA, which decreased net income and diluted EPS by $13.7 billion and $1.75, respectively. Refer to Note 12 – Income Taxes of the Notes to Financial Statements for further discussion.
text: (d) Reflects the impact of the adoption of new accounting standards in fiscal year 2018 related to revenue recognition and leases.
text: (e) LinkedIn has been included in our consolidated results of operations starting on the December 8, 2016 acquisition date.
text: (f) Includes $306 million of employee severance expenses primarily related to our sales and marketing restructuring plan, which decreased operating income, net income, and diluted EPS by $306 million, $243 million, and $0.04, respectively.
text: (g) Includes $630 million of asset impairment charges related to our Phone business and $480 million of restructuring charges associated with our Phone business restructuring plans, which together decreased operating income, net income, and diluted EPS by $1.1 billion, $895 million, and $0.11, respectively.
text: (h) Includes $7.5 billion of goodwill and asset impairment charges related to our Phone business and $2.5 billion of integration and restructuring expenses, primarily associated with our Phone business restructuring plans, which together decreased operating income, net income, and diluted EPS by $10.0 billion, $9.5 billion, and $1.15, respectively.

Questions:
question: Why did net income in 2018 decrease from that in 2017?
answer: Includes a $13.7 billion net charge related to the enactment of the TCJA, which decreased net income and diluted EPS by $13.7 billion and $1.75, respectively.
question: How much would operating income in 2015 have been if there were no goodwill and impairment charges in 2015?
answer: 28161
derivation: 10.0 billion + 18,161 million 
scale: million
question: When was Linkedin acquired?
answer: December 8, 2016
question: When was GitHub acquired?
answer: October 25, 2018
question: What was the total liabilities in 2018?
answer: 176130
derivation: 258,848-82,718
scale: million
question: What was the average revenue over the 3 year period from 2017 to 2019?
answer: 110924.67
derivation: (125,843+110,360+96,571)/(2019-2017+1)
scale: million