Warning: Division by zero  in /var/www/html/donate.worldvision.org/lib/Zend/Cache/Backend/Libmemcached.php on line 395

#0 /var/www/html/donate.worldvision.org/lib/Zend/Cache/Backend/Libmemcached.php(395): mageCoreErrorHandler(2, 'Division by zer...', '/var/www/html/d...', 395, Array)
#1 /var/www/html/donate.worldvision.org/lib/Zend/Cache/Backend/TwoLevels.php(518): Zend_Cache_Backend_Libmemcached->getFillingPercentage()
#2 /var/www/html/donate.worldvision.org/lib/Zend/Cache/Backend/TwoLevels.php(192): Zend_Cache_Backend_TwoLevels->_getFastFillingPercentage('saving')
#3 /var/www/html/donate.worldvision.org/lib/Zend/Cache/Core.php(390): Zend_Cache_Backend_TwoLevels->save('a:0:{}', 'e29_FPC_DESIGN_...', Array, NULL)
#4 /var/www/html/donate.worldvision.org/lib/Varien/Cache/Core.php(145): Zend_Cache_Core->save('a:0:{}', 'FPC_DESIGN_EXCE...', Array, NULL, 8)
#5 /var/www/html/donate.worldvision.org/app/code/core/Mage/Core/Model/Cache.php(403): Varien_Cache_Core->save('a:0:{}', 'FPC_DESIGN_EXCE...', Array, NULL)
#6 /var/www/html/donate.worldvision.org/app/code/core/Enterprise/PageCache/Model/Observer.php(156): Mage_Core_Model_Cache->save('a:0:{}', 'FPC_DESIGN_EXCE...', Array)
#7 /var/www/html/donate.worldvision.org/app/code/core/Enterprise/PageCache/Model/Observer.php(103): Enterprise_PageCache_Model_Observer->_saveDesignException()
#8 /var/www/html/donate.worldvision.org/app/code/core/Mage/Core/Model/App.php(1339): Enterprise_PageCache_Model_Observer->cacheResponse(Object(Varien_Event_Observer))
#9 /var/www/html/donate.worldvision.org/app/code/core/Mage/Core/Model/App.php(1318): Mage_Core_Model_App->_callObserverMethod(Object(Enterprise_PageCache_Model_Observer), 'cacheResponse', Object(Varien_Event_Observer))
#10 /var/www/html/donate.worldvision.org/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('controller_fron...', Array)
#11 /var/www/html/donate.worldvision.org/app/code/core/Mage/Core/Controller/Varien/Front.php(182): Mage::dispatchEvent('controller_fron...', Array)
#12 /var/www/html/donate.worldvision.org/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#13 /var/www/html/donate.worldvision.org/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#14 /var/www/html/donate.worldvision.org/index.php(87): Mage::run('', 'store')
#15 {main}