What was the percentage change in liquefaction services revenue between 2018 and 2019?
{"Statement of income -- Liquefaction services revenue": {"2019": 218096, "2018": 127625}, "Statement of income -- Realized and unrealized (losses)/gains on the oil derivative instrument": {"2019": -26001, "2018": 16767}, "Statement of cash flows -- Net debt repayments": {"2019": -243513, "2018": -30300}, "Statement of cash flows -- Net debt receipts": {"2019": 129454, "2018": "\u2014"}}
liquefaction_services_revenue_2019 = df["Statement of income -- Liquefaction services revenue"]["2019"]
liquefaction_services_revenue_2018 = df["Statement of income -- Liquefaction services revenue"]["2018"]
answer = ( liquefaction_services_revenue_2019 - liquefaction_services_revenue_2018 ) / liquefaction_services_revenue_2018 * 100.0