Turtle Controller, I'm sorry if you have been bored by my little history lesson. You may be well aware of the facts, or maybe you couldn't care less. Either way there's no need to be so snotty.
AndrewH52, according to Revenue and Customs' July 2016 figures the average percentage of the tax take defined as Corporation Tax in the period 1980 to 2016 was 11%, 10% for the last ten years.
What you are ignoring, or perhaps are deliberately not acknowledging, is the way HMRC compiles its figures. All dues collected by government from companies are attributed to the geograhic location of the reporting office. Thus, for instance, Heinz at Kitt Green, Wigan, the biggest food factory in Europe, pays Corporation Tax, VAT, National Insurance contributions (employer and employee) any environmental taxes and business rates through the Hayes Head Office. Its factories in Worcester and Telford also pay through Hayes. Only the business rates are allocated to Wigan, Worcester and Telford.
The same goes for every company in the UK with a site, or sites, outside the Home Counties but with a Head Ofice within which reports and pays the company's tax liabilities. Government is well aware of the location of the generators of tax income but chooses to use the simplest method defining from where it receives its income, yet is happy to state that London has 16.7% of all VAT based businesses, without defining how many are reporting for sites around the UK