What is the change in Bank finance facilities (AUD) Drawn amount from 2018 to 2019?
{"": {"2019": 0, "2018": 0}, "Bank finance facilities (AUD) -- Drawn amount": {"2019": 663800, "2018": 520300}, "Bank finance facilities (AUD) -- Facility limit": {"2019": 680000, "2018": 605000}, "Bank finance facilities (NZD) -- Drawn amount": {"2019": 192250, "2018": 87500}, "Bank finance facilities (NZD) -- Facility limit": {"2019": 196750, "2018": 121000}, "AUD equivalent of NZD facilities -- Drawn amount": {"2019": 184038, "2018": 80048}, "AUD equivalent of NZD facilities -- Facility limit": {"2019": 188346, "2018": 110696}}
bank_finance_facilities_AUD_Drawn_amount_2019 = df["Bank finance facilities (AUD) -- Drawn amount"]["2019"]
bank_finance_facilities_AUD_Drawn_amount_2018 = df["Bank finance facilities (AUD) -- Drawn amount"]["2018"]
answer = bank_finance_facilities_AUD_Drawn_amount_2019 - bank_finance_facilities_AUD_Drawn_amount_2018