pre_text: In 2019, 2018 and 2017, we adopted the revised mortality tables and projection scales released by the Society of Actuaries, which decreased the projected benefit obligation of our benefit plans by $4 million, $38 million and $113 million, respectively. The change in the projected benefit obligation of our benefit plans was recognized as part of the net actuarial (gain) loss and is included in accumulated other comprehensive loss, a portion of which is subject to amortization over the remaining estimated life of plan participants, which was approximately 16 years as of December 31, 2019. The following tables summarize the change in the benefit obligations for the Combined Pension Plan and post-retirement benefit plans:
table: Combined Pension Plan
table: Years Ended December 31,
table: 2019 2018 2017
table: (Dollars in millions)
table: Change in benefit obligation
table: Benefit obligation at beginning of year $11,594 13,064 13,244
table: Service cost 56 66 63
table: Interest cost 436 392 409
table: Plan amendments (9) — —
table: Special termination benefits charge 6 15 —
table: Actuarial (gain) loss 1,249 (765) 586
table: Benefits paid from plan assets (1,115) (1,178) (1,238)
table: Benefit obligation at end of year $12,217 11,594 13,064
question: Analyse this data from a financial earnings document. What is the total special termination benefits charge in 2018 and 2019?