Income per Share

The following is a summary of basic and diluted income per share (in thousands, except share and per share amounts):



	Year Ended December 31,
	2017		2016		2015
Net income available to common stockholders	$	173,148	$	332,088	$	217,266
Weighted average shares outstanding—basic	174,059,386		149,953,662		138,247,606
Potentially dilutive common shares:
Stock options	—		9,726		20,424
Unvested incentive units	141,136		71,031		95,746
Forward equity offering	124,527		3,990		—
Market performance-based awards	570,049		641,279		501,645
Weighted average shares outstanding—diluted	174,895,098		150,679,688		138,865,421
Income per share:
Basic	$	0.99	$	2.21	$	1.57
Diluted	$	0.99	$	2.20	$	1.56

We have excluded the following potentially dilutive securities in the calculations above as they would be antidilutive or not dilutive:



	Year Ended December 31,
	2017	2016	2015
Weighted average of Operating Partnership common units not owned by Digital Realty Trust, Inc.	3,996,550	2,406,018	2,658,291
Potentially dilutive Series C Cumulative Redeemable Perpetual Preferred Stock	540,773	—	—
Potentially dilutive Series E Cumulative Redeemable Preferred Stock	—	2,880,254	4,301,438
Potentially dilutive Series F Cumulative Redeemable Preferred Stock	463,301	1,939,905	2,727,962
Potentially dilutive Series G Cumulative Redeemable Preferred Stock	2,261,153	2,652,503	3,730,042
Potentially dilutive Series H Cumulative Redeemable Preferred Stock	3,313,484	3,886,966	5,465,987
Potentially dilutive Series I Cumulative Redeemable Preferred Stock	2,263,799	2,655,607	1,235,063
Potentially dilutive Series J Cumulative Redeemable Preferred Stock	720,803	—	—
	13,559,863	16,421,253	20,118,783