anyone know why a 1970 dime i dug is not listed in my u.s. coin digest 2008 book....its just a roosevelt dime. i think i see a mint mark but not sure....was just looking in book to pass time, but if u look at their listing it goes to 1969 dimes and skips to 1971 dimes.....the book is by krause publications. just a bit curious if anyone knows....thanks.....mark43