539: interframe interval = 1/29.15 s  avg=1/30.52  stddev=1/76.85

  539: interframe interval = 1/30.57 s  avg=1/30.14  stddev=1/89.24

  527: interframe interval = 1/26.43 s  avg=1/30.72  stddev=1/100.25

  527: interframe interval = 1/28.21 s  avg=1/30.18  stddev=1/84.80

  527: interframe interval = 1/74.33 s  avg=1/30.04  stddev=1/77.77