src/FondOfSpryker/Zed/AvailabilityAlert/Business/Model/SubscribersNotifier.php
protected function calculatePercentageDifference(
        FosAvailabilityAlertSubscription $fosAvailabilityAlertSubscription,
        $countOfSubscriberPerProductAbstract
    ) {
        $fkProductAbstract = $fosAvailabilityAlertSubscription->getFkProductAbstract();
        $subscriberCount = $countOfSubscriberPerProductAbstract[$fkProductAbstract];
        $availability = $this->getAvailability($fosAvailabilityAlertSubscription);

        return $availability * 100 / $subscriberCount;
    }
protected function calculatePercentageDifference(
        FosAvailabilityAlertSubscription $fosAvailabilityAlertSubscription,
        $countOfSubscriberPerProductAbstract
    ) {
        $fkProductAbstract = $fosAvailabilityAlertSubscription->getFkProductAbstract();
        $subscriberCount = $countOfSubscriberPerProductAbstract[$fkProductAbstract];
        $availability = $this->getAvailability($fosAvailabilityAlertSubscription);

        return $availability * 100 / $subscriberCount;
    }
@param \Orm\Zed\AvailabilityAlert\Persistence\FosAvailabilityAlertSubscription $fosAvailabilityAlertSubscription
@param array $countOfSubscriberPerProductAbstract

@return float|int