What was the change in trade receivables from 2018 to 2019?
{"Trade receivables": {"2018": 808, "2019": 9463}, "VAT receivable": {"2018": 1094, "2019": 637}, "Accrued income": {"2018": 9473, "2019": 8274}, "Insurance claims": {"2018": 1282, "2019": 1400}, "Other receivables": {"2018": 7587, "2019": 5126}, "Total": {"2018": 20244, "2019": 24900}}
trade_receivables_2019 = df["Trade receivables"]["2019"]
trade_receivables_2018 = df["Trade receivables"]["2018"]
answer = trade_receivables_2019 - trade_receivables_2018