Please Explain my Increase of 18.7%

Hi Bulb,
By your own information wholesale prices have gone up by 20% since August. Your detailed graph states the wholesale price amounts to about 40% of my bill (Source Bulb Data) so why is my bill going up by 18.6% ?
You do the maths, I’m puzzled.
AFC 23/09/2018

Hi there @Al_49 the 20% increase is an average across the uk, it varies a little more by location, to produce the tariff increases that should be visible on the pdf that came through with that price increase email. It also depends how much electricity and gas you use-gas prices have risen more than electricity, so if you use less gas and more electric your increase will be lower, and vice versa. I hope that helps! If you’d like to talk specifics, you might be better off getting in touch by email or phone, rather than us putting financial stuff on this public forum