print_r($RL_all_years_unique_0);

Array ( [0] => kWh Electricity [1] => Kg Refrigerants [2] => Gallons Diesel [3] => Indirect VMT [4] => Short Tons Solid Waste [5] => Gallons Propane [6] => Cubic Ft Nat Gas [7] => Gallons 87 Gasoline [8] => WasteWater - kg N [9] => WasteWater - Pop )

asort($RL_all_years_unique_0);
print_r($RL_all_years_unique_0);

Array ( [6] => Cubic Ft Nat Gas [7] => Gallons 87 Gasoline [2] => Gallons Diesel [5] => Gallons Propane [3] => Indirect VMT [1] => Kg Refrigerants [4] => Short Tons Solid Waste [9] => WasteWater - Pop [8] => WasteWater - kg N [0] => kWh Electricity )