iPhone 13 maximum capacity battery percentage dropping almost every 2 weeks? Is this normal?

I purchased my iPhone 13 in October 2021 and I lost my first battery percentage in October 2022. It dropped to 97% which I had expected as the phone was a year old. However, I have noticed since then, my phone's maximum battery capacity percentage is dropping quickly and at this rate my iPhone will not even be 2 years old before the maximum battery capacity will be 80%. This is the point where Apple recommends you replace the battery on your phone. I just wanted to know is this normal?

Here is a summary of my phone percentage dropping.

11 February - dropped from 96% to 95%

15 March - dropped to 93%

21 March - dropped to 92%

31 March - dropped to 91% - updated phone to IOS 16.4

13 April - dropped to 90%

Last month I updated my IOS in the hope that it would resolve the issue but the maximum capacity percentage is still dropping.

In terms of usage, I use my phone maximum 6 hours a day and the two apps I mainly use are Instagram and Safari. The only apps that I have downloaded on my phone are Instagram and a banking app.

I still have more than 72GB left on my phone (128GB capacity).

I only use the Apple charger to charge my phone and I try not to charge my phone to more than 85% because when I restart my phone, the battery percentage jumps to 93%. I read that its the amount of charging cycles that reduces your battery and since February I have only been charging my phone when it drops to 15% and try and leave 2 days between charges.

I would appreciate it if anyone had any advice on how to prevent further battery percentage decline because I do not want to have to replace my iPhone after less than 2 years.

Many thanks.