The following information pertains to Havana Corporation's defined benefit pension plan: ($ in thousands) Projected benefit obligation Plan assets Prior service cost-AOCI 2021 Beginning balances $(7,100) 6,800 710 2022 Beginning balances $(7,604) 7,436 660 $ 900 Net loss-AOCI $ 830 At the end of 2021, Havana contributed $680 thousand to the pension fund and benefit payments of $704 thousand were made to retirees. The expected rate of return on plan assets was 11%, and the actuary's discount rate is 7%. There were no changes in actuarial estimates and assumptions regarding the PBO. What is the 2021 service cost for Havana's plan