it's really not often that you see 1964 (90% silver) or 1965 through 1970 (40% silver) Kennedy halves posted as dug on the forums. you have to keep in mind that their release dates were during a time when silver coinage was being phased out. A lot of American people feared the new coinage was going to be worthless, so hoarding of silver coins was common. A lot of the 40% silver halves like the one you found were tucked away as soon as they were received in change. Circulation of them was not really as common place as were Walking Liberty half dollars some years before. By the time clad half dollars were introduced, most people were generally using paper money for most small purchases.