Mine has gone up by 34.5%.
You can work out the percentage with this formula:
[(New rate - Original rate) / Original rate] * 100 = Percentage Increase
New rate minus original rate
Divide that by the original rate
Times it by 100
= % increase
It’s come down 
I discovered I was entitled to a discount which knocked £43 a month off the bill.
Anyone on Pension Credits take noe.