In late 20X0, Security Services Ltd. established a defined benefit pension plan for its employees. At the inception of the plan, the actuary determined the present value of the defined benefit obligation relating to employees’ past services to be $1 million, as of the beginning of 20X1. This amount vests over 10 years.
In each year following inception of the plan, the actuary measured the defined benefit obligation arising from employees’ services in that year. These current service costs amounted to $80,000 in 20X1, $82,000 in 20X2, and $85,000 in 20X3. The costs were determined by using an actuarial cost method based on employees’ projected earnings.

All actuarial obligations and funding payments were determined by assuming an interest rate of 6%, which was the long-term borrowing yield. In accordance with provincial legislation, the past service cost was to be funded over 15 years, the maximum period allowed. Current service costs were to be fully funded at the end of each year.
In 20X4, the actuary conducted the mandatory triennial revaluation. The revaluation revealed that the plan assets at the end of 20X3 were $712,500. The defined benefit obligation at the end of 20X3 was $1,249,800. There was a balance of accumulated OCI of $61,500 (debit) in relation to the pension at the end of 20X3. The actuary also determined that the current service cost for 20X4 was $87,500. There was an experience gain of $21,870 on the pension plan obligation, arising in 20X4, as a result of higher mortality rates. The actual plan earnings for 20X4 were $85,900. At the beginning of 20X4, there was a curtailment of the pension plan, resulting in a reduction in the pension obligation of $75,000 and a reduction in assets of $45,000. There were no benefits paid during the year.

Required:
Determine the amount of pension expense (including interest costs) for 20X4 and the change in accumulated OCI for the year.