What is the percentage change of total balances of contract assets, including current and non-current, from 2018 to 2019?
{"Contract assets, current": {"September 30, 2019": 2350, "October 1, 2018": 169}, "Contract assets, non-current": {"September 30, 2019": 581, "October 1, 2018": 507}, "Contract liabilities, current": {"September 30, 2019": 5612, "October 1, 2018": 4281}, "Contract liabilities, non-current": {"September 30, 2019": 736, "October 1, 2018": 485}}
contract_assets_current_2019 = df["Contract assets, current"]["September 30, 2019"]
contract_assets_noncurrent_2019 = df["Contract assets, non-current"]["September 30, 2019"]
contract_assets_current_2018 = df["Contract assets, current"]["October 1, 2018"]
contract_assets_noncurrent_2018 = df["Contract assets, non-current"]["October 1, 2018"]
answer = ( ( contract_assets_current_2019 + contract_assets_noncurrent_2019 ) - ( contract_assets_current_2018 + contract_assets_noncurrent_2018 ) ) / ( contract_assets_current_2018 + contract_assets_noncurrent_2018 ) * 100.0