The following data are for Guava Company's retiree health care plan for the current calendar year.
Number of employees covered 5
Years employed as of January 1 4 (each)
Attribution period 20 years
EPBO, January 1 $64,000
EPBO, December 31 $69,120
Interest rate 8%
Funding and plan assets None
What is the interest cost to be included in the current year's postretirement benefit expense?