For the Year Ended

December 31,

2019

2018

2017

Numerator (basic and diluted):

Net income

$

1,391,042

$

1,324,487

$

1,133,804

Denominator:

Weighted-average common shares outstanding – basic

76,985

81,406

88,426

Effect of stock options ⁽¹⁾

803

874

1,076

Weighted-average common shares outstanding – assuming dilution

77,788

82,280

89,502

Earnings per share:

Earnings per share-basic

$

18.07

$

16.27

$

12.82

Earnings per share-assuming dilution

$

17.88

$

16.10

$

12.67

Antidilutive potential common shares not included in the calculation of diluted earnings per share:

Stock options ⁽¹⁾

229

567

715

Weighted-average exercise price per share of antidilutive stock options ⁽¹⁾

$

368.11

$

268.55

$

252.16