What is the difference in the total deferred revenues from 2018 to 2019?
{"Cloud services and license support": {"2019": 7340, "2018": 7265}, "Hardware": {"2019": 635, "2018": 645}, "Services": {"2019": 360, "2018": 404}, "Cloud license and on-premise license": {"2019": 39, "2018": 27}, "Deferred revenues, current": {"2019": 8374, "2018": 8341}, "Deferred revenues, non-current (in other non-current liabilities)": {"2019": 669, "2018": 625}, "Total deferred revenues": {"2019": 9043, "2018": 8966}}
total_deferred_revenues_2019 = df["Total deferred revenues"]["2019"]
total_deferred_revenues_2018 = df["Total deferred revenues"]["2018"]
answer = total_deferred_revenues_2019 - total_deferred_revenues_2018