How does one estimate the number of units of a production blade currently in "circulation" so to speak? How many Benchmade Griptilians do you think there are? 100s? 1000s? 10,000s? How many Manix 2s? Even serial numbered productions (Emerson, Microtech) aren't all that helpful in determining how many units of a single knife are out there, as it is difficult to determine how high these numbers go. Does anyone know of any resources or data that might shed some light on this question?