The zone metrics table shows information about all your zones:

Total # entries: The total number of entries in this zone. If the same tag enters a zone twice (enter -> leave -> enter), the total number of entries will be increased with 2.

Total # exits: The total number of exits in this zone. If the same tag leaves a zone twice (leave -> enter -> leave), the total number of exits will be increased with 2.

Min # tags: The minimum number of tags at one point in this zone.

Max # tags: The maximum number of tags at one point in this zone.

Mean # tags: The mean number of tags at one point in this zone.

Mean entry to exit duration: The mean duration between a tag entering a zone and the same tag leaving that zone. If there were 5 different tags, and each one entered the zone, stayed there for 3 seconds, and then left, the mean entry to exit duration would be 3 seconds. If each of those 5 tags did this 5 times, the mean entry to exit duration would still be 3 seconds.

Total duration: The total time that tags have spent in this zone.

Mean duration for tags that went in zone: The mean (total) duration that tags have spent in that zone. If there were 5 different tags, and each one entered the zone, stayed there for 3 seconds, and then left, the mean duration for tags that went in zone would be 3 seconds. If each of those 5 tags did this 5 times, the mean duration for tags that went in zone would be 15 seconds.