What was the change in Issuance of shares under employee stock plans in 2019 from 2018?
{"Net cash provided by operating activities": {"2019": 181401, "2018": 236111}, "Purchases of property and equipment": {"2019": -83283, "2018": -90757}, "Acquisition of businesses, net of cash acquired": {"2019": -18881, "2018": -45448}, "Proceeds from sale of discontinued operation (the Hull Business)": {"2019": "\u2014", "2018": 25000}, "Proceeds from sales of other entities": {"2019": "\u2014", "2018": 6250}, "Borrowings, net of repayments": {"2019": 263, "2018": -173252}, "Issuance of shares under employee stock plans": {"2019": 11811, "2018": 10574}, "Repurchase of common stock": {"2019": -77410, "2018": -100000}, "Net settlement of restricted common stock": {"2019": -15179, "2018": -36320}}
issuance_2019 = df["Issuance of shares under employee stock plans"]["2019"]
issuance_2018 = df["Issuance of shares under employee stock plans"]["2018"]
answer = issuance_2019 - issuance_2018