INVENTORIES



	December 31,
(In millions)	2018		2017
Crude oil and refinery feedstocks	$	3,655	$	2,056
Refined products	5,234		2,839
Materials and supplies	720		494
Merchandise	228		161
Total	$	9,837	$	5,550

The LIFO method accounted for 92 percent and 90 percent of total inventory value at December 31, 2018 and 2017, respectively. There was no excess of replacement or current cost over our stated LIFO cost as of December 31, 2018. Current acquisition costs of inventories were estimated to exceed the LIFO inventory value at December 31, 2017 by $1.21 billion.

During 2017, we recorded LIFO liquidations caused primarily by permanently decreased levels in our crude oil inventory. Cost of revenues increased and income from operations decreased by $7 million for the year ended December 31, 2017 due to LIFO liquidations. There were no material liquidations of LIFO inventories in 2018 and 2016.