What is the increase / (decrease) in products from 2018 to 2019?
{"Products": {"2019": 39003, "2018": 33699, "2017": 38339}, "Support, maintenance and subscription services": {"2019": 75496, "2018": 69068, "2017": 63308}, "Professional services": {"2019": 26343, "2018": 24593, "2017": 26031}, "Total": {"2019": 140842, "2018": 127360, "2017": 127678}}
products_2019 = df["Products"]["2019"]
products_2018 = df["Products"]["2018"]
answer = products_2019 - products_2018