What is the percent of total revenue from residential in the total revenue for the year ended December 31, 2019?
{"Agricultural, Commercial, and Industrial (ACI)": {"2019": 28940, "2018": 33193}, "Public Works": {"2019": 12128, "2018": 17986}, "Residential": {"2019": 18762, "2018": 19786}, "Total": {"2019": 59830, "2018": 70965}}
residential_2019 = df["Residential"]["2019"]
total_2019 = df["Total"]["2019"]
answer = residential_2019 / total_2019 * 100.0