What is the total change in the Adjusted EBITDA margin between 2019 and 2017?
{"Net income (loss)": {"2019": -5269.0, "2018": -1733.0, "2017": 1508.0}, "Income tax expense": {"2019": 503.0, "2018": 170.0, "2017": -770.0}, "Total other expense, net": {"2019": 2040.0, "2018": 2133.0, "2017": 2147.0}, "Depreciation and amortization expense": {"2019": 4829.0, "2018": 5120.0, "2017": 5125.0}, "Share-based compensation expenses": {"2019": 162.0, "2018": 186.0, "2017": 238.0}, "Goodwill impairment": {"2019": 6506.0, "2018": 2726.0, "2017": 0.0}, "Adjusted EBITDA": {"2019": 8771.0, "2018": 8602.0, "2017": 8248.0}, "Exclude: transaction related expenses": {"2019": 0.0, "2018": 0.0, "2017": 192.0}, "Exclude: integration and transformation costs(1)": {"2019": 234.0, "2018": 378.0, "2017": 164.0}, "Exclude: special items(1)": {"2019": 65.0, "2018": 60.0, "2017": 82.0}, "Adjusted EBITDA excluding integration and transformation costs and special items": {"2019": 9070.0, "2018": 9040.0, "2017": 8686.0}, "Total revenue": {"2019": 22401.0, "2018": 23443.0, "2017": 24128.0}, "Adjusted EBITDA Margin": {"2019": 39.2, "2018": 36.7, "2017": 34.2}, "Adjusted EBITDA Margin, excluding integration and transformation costs and special items": {"2019": 40.5, "2018": 38.6, "2017": 36.0}}
adjusted_ebitda_margin_2019 = df["Adjusted EBITDA Margin"]["2019"]
adjusted_ebitda_margin_2017 = df["Adjusted EBITDA Margin"]["2017"]
answer = adjusted_ebitda_margin_2019 - adjusted_ebitda_margin_2017