In 2007, my country’s train speed was increased for the sixth time. The speed of a certain train was increased from 160 kilometers per hour to 200 kilometers per hour. What percentage of the train speed increased?
2007年我国火车第六次提速，某次火车速度从每小时160千米提高到200千米，火车速度提高了百分之几？
<gadget id="calculator">200 - 160</gadget>
<output>40</output>

<gadget id="calculator">40 / 160</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>