But even the Home Office doesn't know the exact number. They know how many current BN(O) holders there are. But they don't know how many are eligible exactly -

But even the Home Office doesn't know the exact number. They know how many current BN(O) holders there are. But they don't know how many are eligible exactly -- they have the entire list of people who have received one, but that's over 20 years ago, and a lot could have happened to them since.