For each metric within the set of metrics, a best data value acquired for {HEAD ~ the metric} from among {TAIL ~ all field web sites} is assigned as a bounding data value for the metric 
For each metric within the set of metrics , a best data value acquired for { HEAD ~ the metric } from among { TAIL ~ all field web sites } is assigned as a bounding data value for the metric
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH