The following table provides a reconciliation between basic and diluted earnings per share for the years ended December 31, 2022, 2021 and 2020:


In millions, except per share data	Year ended December 31,	2022		2021		2020
Net income (1)		$	5,118	$	4,899	$	3,545
Weighted-average basic shares outstanding		686.4		708.5		711.3
Dilutive effect of stock-based compensation		1.9		1.8		1.7
Weighted-average diluted shares outstanding		688.3		710.3		713.0
Basic earnings per share (1)		$	7.46	$	6.91	$	4.98
Diluted earnings per share (1)		$	7.44	$	6.90	$	4.97
Units excluded from the calculation as their inclusion would not have a dilutive effect
Stock options		0.6		0.5		0.7
Performance share units		0.2		0.1		0.3