I don't understand how inflation hasn't gone up by about 20% in the UK - most things seem to have had a huge increase in price with the combination of VAT at 20

I don't understand how inflation hasn't gone up by about 20% in the UK - most things seem to have had a huge increase in price with the combination of VAT at 20% (2011) and the devaluation of the pound I'd say we are already a much poorer country than we were 6-7 years ago.