Basically does anyone know how they work? I was looking at the Spring Equinox Box 2016 percentages (http://wiki.spiralknights.com/Equinox_Prize_Box) and its pretty obvious that all the percentages added together do not equal 100%. (they equal 310% assuming that celestial orbit gun has 1% chance.)

Would I count the odds of getting something that has odds of 18% said as 18/310 or something else?

Thanks for the help,
Sniper