It took only two years for our country to achieve a major leap from the "one-man-one-day" spaceflight of Shenzhou 5 to the "many people, multiple days" spaceflight of Shenzhou 6. The flight time of manned spaceflight increased from 21 hours of Shenzhou 5 to 115.5 hours of Shenzhou 6. By what percentage is the spaceflight time of Shenzhou-6 increased compared with that of Shenzhou-5?
我国仅用两年时间就实现了从神舟五号"一人一天"航天飞行到神舟六号"多人多天"航天飞行的重大跨越．载人航天飞行时间由神舟五号的21小时增加到神舟六号的115.5小时．神舟六号太空飞行时间比神舟五号增加了百分之几？
<gadget id="calculator">115.5 - 21</gadget>
<output>94.5</output>

<gadget id="calculator">94.5 / 21</gadget>
<output>4.5</output>

<result>4.5</result>