I have an issue that my insurance premium increases by 25% per year for the last 2 years

I have an issue that my insurance premium increases by 25% per year for the last 2 years. I have no claims. My no claim bonus is +- 8years. Inflation is @ 3%. How does one get to 25% increase year on year? The explanation I got made no business sense whatsoever. It would be interesting to see if I did have a claim. I assume that the remium would increase would increase by more than 100%. I am dissapointed in this approach Auto & General has adopted.