What’s the perfect hba1c

As a T2 controlling blood glucose by diet and exercise alone ( for now ), I have managed to stabilise my HbA1c at 43. I did get down to 41 but as I am (and always have been) around 9 stone, I find if I restrict carbs too much I can’t keep weight on. So this level is fine for me even if it’s not perfect. My next test is February so that should be interesting following Christmas treats.....