Ancient Alien Theorists predicted this might happen while ruminating on ancient Aztec carvings of the Model Y thousands of years before they actually appeared. Ancient Alien Theorists believe that extraterrestrial visitors must have left the plans for the Model Y on earth for Elon Musk millenia before his birth, just so that this 2-3% fluctuation could prove that Einstein was correct about his theory of Tesla Range Anxiety. This allows the extraterrestrials to refuel their invisible flying saucers with 2-3% of the charge on every Tesla they encounter, through a reverse electrostatic osmosis process, and get away with it with no questions. See, they didn't leave the Model Y plans with the Aztecs so that humanity could develop efficient cars, they left the plans so they could have easy to access fuel stations in every driveway. At least, that's what the Ancient Alien Theorists hypothisize what might be one possible explanation for this unexplainable phenomenon.
-sorry. You'll never guess what's on while I type this...