What was the change in Purchases and leases of products and purchases of services between 2018 and 2019?
{"Purchases and leases of products and purchases of services(1)": {"January 31, 2020": 242, "February 1, 2019": 200, "February 2, 2018": 142}, "Dell subsidiary support and administrative costs": {"January 31, 2020": 119, "February 1, 2019": 145, "February 2, 2018": 212}}
purchases_and_leases_of_products_and_purchases_of_services1_February_1_2019 = df["Purchases and leases of products and purchases of services(1)"]["February 1, 2019"]
purchases_and_leases_of_products_and_purchases_of_services1_February_2_2018 = df["Purchases and leases of products and purchases of services(1)"]["February 2, 2018"]
answer = purchases_and_leases_of_products_and_purchases_of_services1_February_1_2019 - purchases_and_leases_of_products_and_purchases_of_services1_February_2_2018