Income per Unit

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



	Three Months Ended March 31,
	2016		2015
Net income available to common unitholders	$	39,788	$	103,754
Weighted average units outstanding—basic	149,047,798		138,406,993
Potentially dilutive common units:
Stock options	11,286		33,839
Unvested incentive units	122,601		147,874
Market performance-based awards	733,743		242,562
Weighted average units outstanding—diluted	149,915,428		138,831,268
Income per unit:
Basic	$	0.27	$	0.75
Diluted	$	0.27	$	0.75

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



	Three Months Ended March 31,
	2016	2015
Potentially dilutive Series E Cumulative Redeemable Preferred Units	3,345,087	4,392,889
Potentially dilutive Series F Cumulative Redeemable Preferred Units	2,121,447	2,785,960
Potentially dilutive Series G Cumulative Redeemable Preferred Units	2,900,732	3,809,345
Potentially dilutive Series H Cumulative Redeemable Preferred Units	4,250,720	5,582,197
Potentially dilutive Series I Cumulative Redeemable Preferred Units	2,904,126	—
	15,522,112	16,570,391