pre_text: Note 18 Other Post-Employment Benefits and Other Employee Benefit Plans In addition to providing pension benefits, we maintain two Other Post-Employment Benefit Plans which provide a portion of healthcare, dental, vision and life insurance benefits for certain retired legacy employees. These plans are in the U.S. and Canada. Covered employees who retired on or after attaining age 55 and who had rendered at least 10 years of service were entitled to post-retirement healthcare, dental and life insurance benefits. These benefits are subject to deductibles, co-payment provisions and other limitations. The information below relates to these two plans. Contributions made by us, net of Medicare Part D subsidies received in the U.S., are reported below as benefits paid. We may change the benefits at any time. The status of these plans, including a reconciliation of benefit obligations, a reconciliation of plan assets and the funded status of the plans, follows:
table: December 31,
table: (In millions) 2019 2018
table: Change in benefit obligations:
table: Benefit obligation at beginning of period $ 46.4 $ 51.3
table: Service cost — 0.1
table: Interest cost 1.6 1.4
table: Actuarial (gain) loss (1.2) (1.7)
table: Benefits paid, net (3.3) (4.5)
table: Plan amendments — (0.2)
table: Benefit obligation at end of period $ 43.5 $ 46.4
table: Change in plan assets:
table: Fair value of plan assets at beginning of period $ — $ —
table: Employer contribution 3.3 4.5
table: Benefits paid, net (3.3) (4.5)
table: Fair value of plan assets at end of period $ — $ —
table: Net amount recognized:
table: Underfunded status $ (43.5) $ (46.4)
table: Accumulated benefit obligation at end of year $ 43.5 $ 46.4
table: Net amount recognized in consolidated balance sheets consists of:
table: Current liability $ (5.3) $ (5.3)
table: Non-current liability (38.2) (41.1)
table: Net amount recognized $ (43.5) $ (46.4)
table: Amounts recognized in accumulated other comprehensive loss consist of:
table: Net actuarial (gain) loss $ (0.6) $ 0.4
table: Prior service credit (2.6) (3.0)
table: Total $ (3.2) $ (2.6)
question: Analyse this data from a financial earnings document. What is the difference between Benefit obligation at beginning of period for 2018 and 2019?