Target web site data values are compared to {HEAD ~ average and bounding web site data values} at {TAIL ~ a given time} 
Target web site data values are compared to { HEAD ~ average and bounding web site data values } at { TAIL ~ a given time }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL