National total Taxable income

[bodsdad]

Does anyone have any idea what the approximate totals are for a) total of annual niable earnings for the whole of the UK. and b) total of annual taxable earnings taxed at Higher rate (40%) for the whole of the UK.
Reason?  What is the difference to the Inland Revenue between adding 1% to Employee's NI and adding 1% to the Higher Tax rate.  Thus not hitting the pocket of the lower paid.