Reading 18 EOC #9 - Calculating net periodic pension cost

Total periodic pension cost is the change in the net pension liability adjusted for the employer’s contribution into the plan. The net pension liability increased from 3,000 to 3,020

How do you arrive at the 3000 and 3020 numbers?

Never mind - figured it out. It’s the benefit obligation minus plan assets at beginning of year and do the same for end of year.