What was the percentage change in trade receivables in 2019 from 2018?
{"": {"31 March 2019": "$M", "31 March 2018 Restated See note 2": "$M"}, "Current -- Trade receivables": {"31 March 2019": 128.7, "31 March 2018 Restated See note 2": 151.8}, "Current -- Prepayments": {"31 March 2019": 26.9, "31 March 2018 Restated See note 2": 23.1}, "Current -- Deferral of contract acquisition costs": {"31 March 2019": 31.5, "31 March 2018 Restated See note 2": 29.5}, "Current -- Other receivables": {"31 March 2019": 8.2, "31 March 2018 Restated See note 2": 6.4}, "Current -- Total current trade and other receivables": {"31 March 2019": 195.3, "31 March 2018 Restated See note 2": 210.8}, "Non-current -- Deferral of contract acquisition costs": {"31 March 2019": 15.1, "31 March 2018 Restated See note 2": 16.2}, "Non-current -- Other receivables": {"31 March 2019": 1.3, "31 March 2018 Restated See note 2": 1.3}, "Non-current -- Total non-current trade and other receivables": {"31 March 2019": 16.4, "31 March 2018 Restated See note 2": 17.5}}
trade_receivables_2019 = df["Current -- Trade receivables"]["31 March 2019"]
trade_receivables_2018 = df["Current -- Trade receivables"]["31 March 2018 Restated See note 2"]
answer = (trade_receivables_2019 - trade_receivables_2018) / trade_receivables_2018 * 100.0