what does it mean if same IOP avg, but std. deviation varies?

Consider the following two series of AT555 IOP measurements (both taken from the same eye):

   a) 8:51am:  12,12,17 --- avg. 13.7  

  b) 9:00am:  13,14,14  -- avg: 13.7

The first reading shows a much wider variation in IOP (5 points) than the second, however both have the exact same average (13.7).  

Q#1: would a Goldman Applanation Tonomoter (which reports average IOP, I believe) have reported 13.7 in both cases?