NavList:

"I'll suggest a different measure by which to count the world's celestial navigators: how many people shot a celestial sight with a manual instrument like a common sextant within the past year and used it in some fashion immediately after taking the sight to get useful navigational information, outside of a school or classroom scenario, whether they had to review using a book or not? I would estimate 5000 at sea, maximum."

Frank,

I would think that the number of people who take celestrial sights and USE it for something would be close to zero. 
Almost always folk in this group compare their cel shot to their GPS position.  Unless there is a race that has rules saying you cannot use GPS then the cel nav is more of a hobby.

Don't get me wrong - I love knowing how to find my position using the sun and stars but would never ( in this day and age ) use it as my only way or even my primary way of position finding. I do it for fun.

John H.