<prompt> Translate the following text to EnglishKwa msingi wa gharama kwa kipande, gharama za jiji ni chini ya asilimia 8 kwa kutumia gharama halisi za kazi na chini ya asilimia 21 kwa kutumia wastani wa gharama za kazi za mazungumzo.  <response>: On a cost-per-piece basis, city costs are 8 percent lower using actual labor costs and 21 percent lower using the average bargaining labor costs. 