7. Inventory

Non-core inventory, inventory unreturned, long-term core inventory, and long-term core inventory deposits are as follows at March 31:

	2018			2017
Non-core inventory
Raw materials	$	25,805,000		$	21,515,000
Work in process		635,000			641,000
Finished goods		53,973,000			48,337,000
		80,413,000			70,493,000
Less allowance for excess and obsolete inventory		(4,138,000	)		(2,977,000	)
Total	$	76,275,000		$	67,516,000

Inventory unreturned	$	7,508,000		$	7,581,000

Long-term core inventory
Used cores held at the Company's facilities	$	53,278,000		$	38,713,000
Used cores expected to be returned by customers		12,970,000			11,752,000
Remanufactured cores held in finished goods		34,201,000			27,667,000
Remanufactured cores held at customers' locations (1)		203,751,000			185,938,000
		304,200,000			264,070,000
Less allowance for excess and obsolete inventory		(2,544,000	)		(1,148,000	)
Total	$	301,656,000		$	262,922,000

Long-term core inventory deposits	$	5,569,000		$	5,569,000

(1)	Remanufactured cores held at customers’ locations represent the core portion of the Company’s customers’ finished goods at the Company’s customers’ locations.