What is the change in Net sales of North America between 2018 and 2019?
{"NorthAmerica": {"2019": 6024305, "2018": 5362981, "%Change": 12}, "EMEA": {"2019": 1526644, "2018": 1530241, "%Change": "\u2014"}, "APAC": {"2019": 180241, "2018": 186914, "%Change": -4}, "Consolidated": {"2019": 7731190, "2018": 7080136, "%Change": 9}}
north_america_2019 = df["NorthAmerica"]["2019"]
north_america_2018 = df["NorthAmerica"]["2018"]
answer = north_america_2019 - north_america_2018