iPhone 13 Battery Health

Hi, I’ve had my iPhone 13 for a little more than a year at this point and i checked my battery health to check where it was at. To my surprise, it had dropped 9% to now only be at 91% battery health. After doing research on what might have caused that I noticed a recurring theme about 5g having an effect on my battery health. I just wanted to verify what could be causing the fast deterioration of my battery health and if there’s anything I can do to slow down the loss of the battery.