What is the change in Interest rate swaps (AUD) at face value for Future interest rate swaps from 2018 to 2019?
{"": {"2019": 0, "2018": 0}, "Interest rate swaps (AUD) at face value -- Current interest rate swaps": {"2019": 400000, "2018": 270000}, "Interest rate swaps (AUD) at face value -- Future interest rate swaps": {"2019": 275000, "2018": 400000}, "Interest rate swaps (NZD) at face value -- Current interest rate swaps": {"2019": 73500, "2018": 53500}, "Interest rate swaps (NZD) at face value -- Future interest rate swaps": {"2019": 50000, "2018": 100000}, "AUD equivalent of NZD interest rate swaps -- Current interest rate swaps": {"2019": 70361, "2018": 48944}, "AUD equivalent of NZD interest rate swaps -- Future interest rate swaps": {"2019": 47864, "2018": 91485}}
interest_rate_swap_AUD_at_face_value_future_2019 = df["Interest rate swaps (AUD) at face value -- Future interest rate swaps"]["2019"]
interest_rate_swap_AUD_at_face_value_current_2019 = df["Interest rate swaps (AUD) at face value -- Current interest rate swaps"]["2019"]
answer = interest_rate_swap_AUD_at_face_value_future_2019 - interest_rate_swap_AUD_at_face_value_current_2019