Laptop battery worn 9% in two months, is it normal?

I just got a new laptop which is just 2 months old running Windows 10. Today when I checked the battery life the battery has worn down 9% which is like 4.5% per month, in this rate my battery would only last close to two years or less.

What's the average wear rate of the laptop battery? I use the laptop plugged in most of the time how ever let it drain (not completely) and charge it back once in a week. So a 9% drop is like 50 charging cycles which it definitely didn't had.

So this much of wearing is normal or too much? average wear rate of the laptop battery?

Of course this is assuming that the battery was 100% by the time I bought it, being a brand new laptop I assume that it should be close to 100%.