Hrm... come to think of it, there are some people who would want to have a list of off-grid mountain men (hunters of potential immortal vampires? or perhaps to ensure that such people have their... ahem "votes" properly counted?), so even then there surely is a list, or rather a few thousand lists, of such people? Perhaps all people who have not bought anything for the last 5 years but for where an obituary has not yet recorded their deaths?

(Unfortunately) where there is a will, there is a way!