Don't worry about it enjoy your new MacBook. There are many variables; charging temperature, operating temperature, usage. In short the battery "health" is variable, not an absolute, subsequently nothing worth being worried about 🙂
Your battery is fine. It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. The gradual decline is not in a straight line downward, and it may decline more rapidly at some times and slower at others. For further details, read the CHECKING STATUS AND HEALTH section of the following link.
The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
Don't worry about it enjoy your new MacBook. There are many variables; charging temperature, operating temperature, usage. In short the battery "health" is variable, not an absolute, subsequently nothing worth being worried about 🙂
I remember after one of the iPhone launches, so many people were freaking out about the rate at which their batteries were declining. I could just picture them sitting there staring at their screens a thousand times each day, not realizing that monitoring the battery that obsessively was what, in fact, was causing the decline.