What was the change in balance of unrecognized tax benefits at the end of the year between 2018 and 2019?
{"Balance of unrecognized tax benefits at beginning of year": {"2019": 28406, "2018": 27237, "2017": 24278}, "Increases for tax positions of prior years": {"2019": 2784, "2018": 315, "2017": 2478}, "Decreases for tax positions of prior years": {"2019": -96, "2018": -61, "2017": -114}, "Increases for tax positions established for the current period": {"2019": 2542, "2018": 1185, "2017": 1677}, "Decreases for settlements with taxing authorities": {"2019": -220, "2018": "\u2014", "2017": -154}, "Reductions resulting from lapse of applicable statute of limitation": {"2019": -4462, "2018": -115, "2017": -1155}, "Adjustment resulting from foreign currency translation": {"2019": 46, "2018": -155, "2017": 227}, "Balance of unrecognized tax benefits at end of year": {"2019": 29000, "2018": 28406, "2017": 27237}}
balance_2019 = df["Balance of unrecognized tax benefits at end of year"]["2019"]
balance_2018 = df["Balance of unrecognized tax benefits at beginning of year"]["2019"]
answer = balance_2019 - balance_2018