What is the increase/ (decrease) in Cash and restricted cash from December 31, 2019 to December 31, 2018?
{"": {"2019": "$", "2018": "$"}, "Cash and restricted cash": {"2019": 379085, "2018": 568843}, "Other assets  current": {"2019": 148663, "2018": 412388}, "Vessels and equipment, including vessels related to finance leases and advances on  Vessels and equipment, including vessels related to finance leases and advances on newbuilding contracts": {"2019": 3123377, "2018": 6615077}, "Net investment in direct financing leases": {"2019": 4469861, "2018": 3000927}, "Other assets  non-current": {"2019": 169925, "2018": 1957271}, "Current portion of long-term debt and obligations related to finance leases": {"2019": 563776, "2018": 1106812}, "Other liabilities  current": {"2019": 189165, "2018": 563862}, "Long-term debt and obligations related to finance leases": {"2019": 5156307, "2018": 6882426}, "Other liabilities  non-current": {"2019": 243301, "2018": 478311}}
cash_2019 = df["Cash and restricted cash"]["2019"]
cash_2018 = df["Cash and restricted cash"]["2018"]
answer = cash_2019 - cash_2018