Sorry I do not know this, I know that before the ban hunting with hounds culled 21,000-25,000 foxes annually and there was 196 registered hound packs. It depends on the size of the group and how frequently they go out.
If someone else knows, that would be great.
You do not have to have hunted foxes to fill in the survey, if you hunt some other species that information could be used as well.