It simply rounds percentages to two decimal digits, and when those two digits are zero, they are hidden. For example, see: http://www.wolframalpha.com/input/?i=

It simply rounds percentages to two decimal digits, and when those two digits are zero, they are hidden. For example, see: http://www.wolframalpha.com/input/?i=%28e^pi-pi%29*100%25 http://www.wolframalpha.com/input/?i=%28e^pi-pi%29*100%25