@ Clark October 3, 2019 at 19:43
I wish you well with the demos; it appears the police are planning new restrictions.
Rather than trying to explain the maths to me (I did all right with algebra and geometry, but gave up on square roots and logs, to say nothing of trigonometry), why don’t you present your findings to A&E? It can’t do any harm, and it would not be difficult to email them.