In 2016 Scotland exported£6 billion of goods and services to ruk. I'll let you guess if gers for that year took account of this. And when I say exported we didn't get paid for them. Things like electricity, of which Scotland produces 25% more than it uses.
London, according to the UK government, exported fifty tonnes of salmon. London doesn't produce any salmon.
25 of the 26 figures in gets are provided by London. Many of which are estimates.
If you believe that you'll be very interested in this bridge I have for sale.