<Tr> <Td> Proportion 2015 </Td> <Td> 32.63% </Td> <Td> 0.68% </Td> <Td> 32.49% </Td> <Td> 65.81% </Td> <Td> 19.24% </Td> <Td> 6.01% </Td> <Td> 0.38% </Td> <Td> 0.60% </Td> <Td> 4.6% </Td> <Td> 01.01% </Td> <Td> 0.52% </Td> <Td> 13.13% </Td> <Td> 1.82% </Td> <Td> 100.0% </Td> </Tr> <Tr> <Td> 2014 </Td> <Td> 1,581.71 </Td> <Td> 30.23 </Td> <Td> 1,138.63 </Td> <Td> 2,750.57 </Td> <Td> 797.17 </Td> <Td> 259.37 </Td> <Td> 15.88 </Td> <Td> 17.69 </Td> <Td> 181.655 </Td> <Td> 42.34 </Td> <Td> 21.65 </Td> <Td> 538.58 </Td> <Td> 60.50 </Td> <Td> 4,146.2 </Td> </Tr> <Tr> <Td> 2013 </Td> <Td> 1,581.12 </Td> <Td> 27.16 </Td> <Td> 1,137.69 </Td> <Td> 2,745.97 </Td> <Td> 789.02 </Td> <Td> 268.57 </Td> <Td> 15.78 </Td> <Td> 9.04 </Td> <Td> 167.84 </Td> <Td> 40 </Td> <Td> 20.83 </Td> <Td> 522.07 </Td> <Td> 55.64 </Td> <Td> 4,112.7 </Td> </Tr> <Tr> <Td> 2012 </Td> <Td> 1,514.04 </Td> <Td> 23.19 </Td> <Td> 1,237.79 </Td> <Td> 2,775.02 </Td> <Td> 769.33 </Td> <Td> 276.24 </Td> <Td> 15.56 </Td> <Td> 4.33 </Td> <Td> 140.82 </Td> <Td> 37.8 </Td> <Td> 19.82 </Td> <Td> 494.57 </Td> <Td> 56.1 </Td> <Td> 4095 </Td> </Tr>

What percent of the energy generated in the united states is for transportation