Opicio al pidil is uie data. a. (For general readers.) Assume that the Department of Energy breaks down energy consumption in the United States (by source) into these percentages: In 1980, coal, 18.5; natural gas, 32.8; hydro and geothermal, 3.1; nuclear, 1.2; oil, 44.4. In 1990, coal, 20.3; natural gas, 26.9; hydro and geothermal, 3.8; nuclear, 4.0; oil, 45.0. In 2000, coal, 23.5; natural gas, 23.8; hydro and geothermal, 7.3; nuclear, 4.1: oil, 41.3. In 2010, coal, 20.3; Opicio al pidil is uie data. a. (For general readers.) Assume that the Department of Energy breaks down energy consumption in the United States (by source) into these percentages: In 1980, coal, 18.5; natural gas, 32.8; hydro and geothermal, 3.1; nuclear, 1.2; oil, 44.4. In 1990, coal, 20.3; natural gas, 26.9; hydro and geothermal, 3.8; nuclear, 4.0; oil, 45.0. In 2000, coal, 23.5; natural gas, 23.8; hydro and geothermal, 7.3; nuclear, 4.1: oil, 41.3. In 2010, coal, 20.3