Income per Unit

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



	Year Ended December 31,
	2016		2015		2014
Net income available to common unitholders	$	337,386	$	220,343	$	135,485
Weighted average units outstanding—basic	152,359,680		140,905,897		136,122,661
Potentially dilutive common units:
Stock options	9,726		20,424		30,434
Unvested incentive units	71,031		95,746		90,449
Forward equity offering	3,990		—		—
Market performance-based awards	641,279		501,645		147,305
Weighted average units outstanding—diluted	153,085,706		141,523,712		136,390,849
Income per unit:
Basic	$	2.21	$	1.56	$	1.00
Diluted	$	2.20	$	1.55	$	0.99

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



	Year Ended December 31,
	2016	2015	2014
Potentially dilutive 2029 Debentures	—	—	1,957,963
Potentially dilutive Series E Cumulative Redeemable Preferred Units	2,880,254	4,301,438	4,956,175
Potentially dilutive Series F Cumulative Redeemable Preferred Units	1,939,905	2,727,962	3,143,195
Potentially dilutive Series G Cumulative Redeemable Preferred Units	2,652,503	3,730,042	4,297,805
Potentially dilutive Series H Cumulative Redeemable Preferred Units	3,886,966	5,465,987	4,320,495
Potentially dilutive Series I Cumulative Redeemable Preferred Units	2,655,607	1,235,063	—
	14,015,235	17,460,492	18,675,633