During the year, how did the surplus of the US pension fund change, considering that at the end of 2017, it had assets valued at USD 840 million and liabilities valued at USD 450 million? The assets were fully invested in equities and commodities, while the liabilities were exclusively in fixed-income instruments. By the end of 2018, the value of the assets decreased by 14.0%, and the value of the liabilities increased by 3.5%. No changes were made to the asset and liability allocations throughout the year.