Unidentified aerial vehicles

Currently waiting for a response from Ministry of Defence, they should respond promptly and normally no later than (details).

Dear Ministry of Defence,

How many unidentified aerial vehicles has the MoD and its various forces detected and/or tracked over the last decade both within British airspace, and outside of it?

What is the procedure for dealing with unidentified aerial vehicles or phenomena?

Yours faithfully,

Adam K Dean