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 $ 68,480 Interest rate 7 % Funding and plan assets None What is the service cost to be included in the current year's postretirement benefit expense?