Note 5. Inventories

Our inventory amounts by product type were as follows at the dates indicated:

	June 30, 2014		December 31, 2013
NGLs	$	617.8	$	593.8
Petrochemicals and refined products		300.8		395.1
Crude oil		368.9		42.6
Natural gas		30.8		61.6
Total	$	1,318.3	$	1,093.1

Due to fluctuating commodity prices, we recognize lower of cost or market adjustments when the carrying value of our available-for-sale inventories exceeds their net realizable value. The following table presents our total cost of sales amounts and lower of cost or market adjustments for the periods indicated:

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2014		2013		2014		2013
Cost of sales (1)	$	10,705.3	$	9,458.3	$	21,758.0	$	19,150.8
Lower of cost or market adjustments		2.7		7.7		7.9		10.4
(1) Cost of sales is a component of "Operating costs and expenses" as presented on our Unaudited Condensed Statements of Consolidated Operations. Period-to-period fluctuations in these amounts are primarily due to changes in energy commodity prices and sales volumes associated with our marketing activities.