Mark, Inc. amended its defined benefit pension plan as of January 1, 2020. Mark received a report from its actuary stating that at the beginning of 2020 unrecognized prior service cost resulting from the amendment amounted to $144,000. The company's work force was composed of twelve people. Four were expected to retire at the end of 2022. Two were expected to retire at the end of 2024, two more at the end of 2026, and four at the end of 2028.