It could very well be a common date now. The key dates were mostly kept out during the Great Melts while the common dates were melted. Theres no way of knowing but a common date could very well be less common now and rare dates could be more common. Literally truckloads of bags of constitutional silver has been melted. None of the original minting numbers are close to accurate since the Great Melts and key dates dont mean much anymore. Even half of the silver dollars were melted after ww1.