A car used to run 100 kilometers with 15.5 liters of gasoline, but now it only uses 12.6 liters of gasoline for 100 kilometers. How many liters of gasoline are saved on average per kilometer now than in the past?
一种小汽车过去行驶100千米用汽油15.5升，经技术改造后，现在行驶100千米只用汽油12.6升．现在平均每千米比过去节约汽油多少升？
<gadget id="calculator">15.5 / 100</gadget>
<output>0.155</output>

<gadget id="calculator">12.6 / 100</gadget>
<output>0.126</output>

<gadget id="calculator">0.155 - 0.126</gadget>
<output>0.029</output>

<result>0.029</result>