“…The toughness [13], the integrity [8], the domination number [16], the bondage number [5,6], the edge eccentric connectivity number [28], etc., have been proposed for measuring the vulnerability of networks. Recently, some average vulnerability parameters like the average lower independence number [4,17], the average lower domination number [2,7,11,17,23], the average connectivity number [10], the average lower connectivity number [1] and the average lower bondage number [24] have been defined.…”