FRAPS is counting the time of every frame.
166fps minimum is clearly incorrect, and is probably a 1s average. A ~20ms frame is a ~50fps minimum frame rate. The 1% and .01% frame rates are there to cull extreme outliers like that.
I'd argue, that in this case, the 0.1% is far more useful than that misleading average figure, or the single frame out of ~33k frames that falls significantly outside the rest.
...rightful liberty is unobstructed action according to our will within limits drawn around us by the equal rights of others. I do not add 'within the limits of the law,' because law is often but the tyrant's will, and always so when it violates the right of an individual. -- Thomas Jefferson