something other than 13.1

I was driving with my daughter recently and saw an oval sticker on the back of a car which simply said 13.1.  I commented on it and my daughter explained that it indicated someone who had successfully completed a half marathon.  She went on to say that if you finish a full marathon you can get a sticker that says 26.2. It got me thinking about what sort of sticker I could put on my car, maybe 0.1 if we're talking running.  I actually can walk a mile so maybe W1?  I did a two mile hike recently up and down a fairly steep hill.  Perhaps /\2?