What is the increase / (decrease) in the total revenue from 2018 to 2019?
{"": {"December 31, 2019": "", "September 29, 2019": "", "December 31, 2018": "(Unaudited, in millions)", "Sequential": "", "Year-Over-Year": ""}, "EMEA": {"December 31, 2019": 538.0, "September 29, 2019": 549.0, "December 31, 2018": 617.0, "Sequential": -2.0, "Year-Over-Year": -12.8}, "Americas": {"December 31, 2019": 360.0, "September 29, 2019": 326.0, "December 31, 2018": 342.0, "Sequential": 10.5, "Year-Over-Year": 5.4}, "Asia Pacific": {"December 31, 2019": 1856.0, "September 29, 2019": 1678.0, "December 31, 2018": 1689.0, "Sequential": 10.6, "Year-Over-Year": 9.9}, "Total": {"December 31, 2019": 2754.0, "September 29, 2019": 2553.0, "December 31, 2018": 2648.0, "Sequential": 7.9, "Year-Over-Year": 4.0}}
total_2019 = df["Total"]["December 31, 2019"]
total_2018 = df["Total"]["December 31, 2018"]
answer = total_2019 - total_2018