Electronic Distribution has a defined benefit pension plan. Characteristics of the plan during 2018 are as follows: millions) S 480 300 75 45 PBO balance, January 1 Plan assets balance, January 1 Service cost nterest cost Gain from change in actuarial assumption Benefits paid Actual return on plan assets Contributions 2018 (36) 20 60 The expected long-term rate of return on plan assets was 8%. There were no AOCI balances related to pensions on January 1, 2018, but at the end of 2018, the company amended the pension formula creating a prior service cost of $12 million