What was the sum of customer incentives and capitalised transaction costs in 2019?
{"Customer incentives": {"Note": 6, "30 June 2019 $'000": 1091, "30 June 2018 $'000": 1145}, "Capitalised transaction costs": {"Note": "", "30 June 2019 $'000": 3359, "30 June 2018 $'000": 5490}, "Contract costs": {"Note": 6, "30 June 2019 $'000": 448, "30 June 2018 $'000": "-"}, "Total other assets - non-current": {"Note": "", "30 June 2019 $'000": 4898, "30 June 2018 $'000": 6635}}
customer_incentives = df["Customer incentives"]["30 June 2019 $'000"]
capitalised_transaction_costs = df["Capitalised transaction costs"]["30 June 2019 $'000"]
answer = customer_incentives + capitalised_transaction_costs