setPercentageDiscount example

$customerGroup->setName($data['__customerGroup_description']);

        $customerGroup->setDisplayGrossPrices((bool) $data['__customerGroup_tax']);

        $customerGroup->setInsertedGrossPrices((bool) $data['__customerGroup_taxinput']);

        $customerGroup->setKey($data['__customerGroup_groupkey']);

        $customerGroup->setMinimumOrderValue((float) $data['__customerGroup_minimumorder']);

        $customerGroup->setPercentageDiscount((float) $data['__customerGroup_discount']);

        $customerGroup->setSurcharge((float) $data['__customerGroup_minimumordersurcharge']);

        $customerGroup->setUseDiscount((bool) $data['__customerGroup_mode']);

        if (!empty($data['__customerGroupAttribute_id'])) {
            $this->attributeHydrator->addAttribute($customerGroup, $data, 'customerGroupAttribute');
        }

        return $customerGroup;
    }
}