What is the difference between notes receivables from 2018 to 2019?
{"Prepaid expenses": {"2019": 137927, "2018": 90981}, "Prepaid income taxes .": {"2019": 47811, "2018": 59319}, "Indirect tax receivables .": {"2019": 29908, "2018": 26327}, "Restricted cash": {"2019": 13697, "2018": 19671}, "Notes receivable (1)": {"2019": 23873, "2018": 5196}, "Derivative instruments (2) .": {"2019": 1199, "2018": 2364}, "Other current assets": {"2019": 22040, "2018": 39203}, "Prepaid expenses and other current assets": {"2019": 276455, "2018": 243061}}
notes_receivable_1_2019 = df["Notes receivable (1)"]["2019"]
notes_receivable_1_2018 = df["Notes receivable (1)"]["2018"]
answer = notes_receivable_1_2019 - notes_receivable_1_2018