What was the change in the year-on-year percentage change in GDP for Germany from 2018 to 2019?
{"World": {"20181": 3.6, "20192": 2.9}, "Germany": {"20181": 1.5, "20192": 0.6}, "Western Europe (excl.Germany)": {"20181": 1.9, "20192": 1.3}, "Russia": {"20181": 2.3, "20192": 1.1}, "Eastern Europe (excl.Russia)": {"20181": 4.1, "20192": 3.6}, "Asia": {"20181": 5.6, "20192": 4.9}}
germany_20192 = df["Germany"]["20192"]
germany_20181 = df["Germany"]["20181"]
answer = germany_20192 - germany_20181