PENSION AND OTHER POSTRETIREMENT BENEFITS

The components of net periodic pension and postretirement health benefit costs were as follows:



	Pension Benefits
	(in thousands)
	For the Three Months Ended April 30,						For the Nine Months Ended April 30,
	2019			2018			2019			2018
Service cost	$	407		$	431		$	1,220		$	1,293
Interest cost	529			503			1,586			1,517
Expected return on plan assets	(702		)	(656		)	(2,107		)	(1,627		)
Amortization of:
Prior service costs	—			1			1			2
Other actuarial loss	192			314			578			955
Net periodic benefit cost	$	426		$	593		$	1,278		$	2,140

	Postretirement Health Benefits
	(in thousands)
	For the Three Months Ended April 30,						For the Nine Months Ended April 30,
	2019			2018			2019			2018
Service cost	$	27		$	26		$	79		$	80
Interest cost	24			20			73			63
Amortization of:
Prior service costs	(2		)	(2		)	(5		)	(5		)
Other actuarial loss	—			—			—			—
Net periodic benefit cost	$	49		$	44		$	147		$	138

The non-service cost components of net periodic benefit cost are included in Other Income (Expense) in the line item Other, net on the unaudited Condensed Consolidated Statements of Income and Retained Earnings.

The pension plan is funded based upon actuarially determined contributions that take into account the amount deductible for income tax purposes, the normal cost and the minimum contribution required and the maximum contribution allowed under applicable regulations. We were not required to make, and did not make, a contribution to the pension plan during the first nine months of fiscal year 2019. We have no minimum funding requirements for the remainder of fiscal year 2019.

We made a significant voluntary contribution to the pension plan in excess of the minimum required contribution in the third quarter of fiscal year 2018. This voluntary contribution improved the plan's funded status and contributed to a lower net periodic benefit expense for the third quarter and the first nine months of fiscal year 2019 compared to the same period in the prior year. The postretirement health plan is an unfunded plan. We pay insurance premiums and claims from our assets.

Assumptions used in the previous calculations were as follows:



	Pension Benefits				Postretirement Health Benefits
	For the Three and Nine Months Ended April 30,
	2019		2018		2019		2018
Discount rate for net periodic benefit cost	4.04	%	3.75	%	3.81	%	3.26	%
Rate of increase in compensation levels	3.50	%	3.50	%	—		—
Long-term expected rate of return on assets	7.00	%	7.00	%	—		—

The medical cost trend assumption for postretirement health benefits was 7.50%. The graded trend rate is expected to decrease to an ultimate rate of 4.50% in fiscal year 2038.