4. Agreement of Limited Partnership

We make quarterly distributions to holders of our General Partner interest and Limited Partner interests based on Available Cash for the quarter as defined in our agreement of limited partnership. Available Cash is defined generally as all cash receipts less all cash disbursements, less certain reserves (including reserves for future operating and capital needs) established as the General Partner determines in its reasonable discretion to be necessary or appropriate. Changes in working capital affect Available Cash as changes in the amount of cash invested in working capital items (such as increases in inventory and decreases in accounts payable) reduce Available Cash, while declines in the amount of cash invested in working capital items increase Available Cash. We paid distributions of $465.2 million, $558.3 million and $448.7 million to our partners in 2013, 2012 and 2011, respectively.

We receive 99 percent of the Available Cash from the Operating Partnership and 1 percent is distributed to its General Partner. Cash distributions from the Operating Partnership generally represent the Operating Partnership's Available Cash from operations. Our cash distributions are made 99.975 percent to common and Class B common unitholders and 0.025 percent to our General Partner except when cumulative distributions of Available Cash exceed specified target levels above the Minimum Quarterly Distributions (MQD) of $0.605 per unit. Under such circumstances, our General Partner is entitled to receive Incentive Distribution Rights.

On February 10, 2014, we announced a $2.10 cash distribution per common unit, payable on February 28, 2014 to holders of record as of February 21, 2014. In the fourth quarter of 2013, we exceeded the cumulative MQD amounts and will distribute Available Cash as summarized in the following table:

	Income and Distribution Allocation

	Target Limit		Target Increment		Common Units			Class B Common Units			General Partner			Total
Minimum Quarterly Distributions	$	0.605	$	0.605		98.990	%		0.985	%		0.025	%		100.00	%
First Target		0.715		0.110		98.990	%		0.985	%		0.025	%		100.00	%
Second Target		0.825		0.110		85.859	%		0.985	%		13.156	%		100.00	%
Third Target		1.045		0.220		75.758	%		0.985	%		23.257	%		100.00	%
Final Target and Beyond		>1.045		—		50.505	%		0.985	%		48.510	%		100.00	%

The General Partner is required to remit the majority of cash distributions it receives from the Partnership, in excess of its 1 percent Partnership equity interest, to an affiliated company.

The quarterly cash distributions paid to the unitholders and the General Partner in 2013 and 2012 follow:

		Common Units				Class B Common Units				General Partner

		Total		Per unit		Total		Per unit		Total
		(in millions, except per unit amounts)
2013
	First Quarter	$	67.2	$	3.63	$	1.2	$	6.25	$	49.5
	Second Quarter		86.6		4.68		1.5		8.31		68.6
	Third Quarter		74.4		4.02		1.3		7.00		56.5
	Fourth Quarter		37.4		2.02		0.6		3.09		20.4
2012
	First Quarter	$	83.8	$	4.53	$	1.5	$	8.01	$	65.9
	Second Quarter		74.0		4.00		1.3		6.96		56.2
	Third Quarter		77.9		4.21		1.3		7.39		60.2
	Fourth Quarter		76.4		4.12		1.3		7.21		58.5

At December 31, 2013, the General Partner and its affiliates owned 75.3% of our outstanding units. When not more than 25% of our issued and outstanding units are held by non-affiliates of the General Partner, we, at the General Partner's sole discretion, may call, or assign to the General Partner or its affiliates, our right to acquire all such outstanding units held by non-affiliated persons. If the General Partner elects to acquire all outstanding units, we are required to give at least 30 but not more than 60 days notice of our decision to purchase the outstanding units. The purchase price per unit will be the greater of (1) the average of the previous 20 trading days' closing prices as of the date five days before the purchase is announced or (2) the highest price paid by the General Partner or any of its affiliates for any unit within the 90 days preceding the date the purchase is announced.