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ADXRS453 gyro never outputs -1

I am starting to use an ADXRS453 gyro in a small circuit driven by an ARM MCU.  I created a histogram of output values while the gyro was sitting still to evaluate null performance.  I found that the gyro never outputs the value -1.  I tested with two units, and both showed the same behavior.  One ranged from -31 to 60, averaging 20; the other -61 to 29, averaging -11.  Over thousands of samples, all values within those ranges were present except -1 (0xFFFF).

My conclusion is the unit does output 0xFFFF, and -1 is actually represented by the hex value 0xFFFE.  This means that Table 15 in the data sheet labeled Rate Data is wrong, as -20 would be represented by 0xFFEB and so on.  The most negative hex value of 0x8000 would be -32767 instead of -32768.

I wonder if anyone else can confirm this behavior.  Ideally, it would nice to get a confirmation or explanation from ADI.  If I'm correct, the data sheet should be updated and this may also affect other similar devices.