<prompt> Translate the following text to EnglishKwa kuongezea, isipokuwa Huduma ya Posta haiwezi kupunguza gharama za kubadilika kwa kiasi au inangoja hadi 2008 kabla ya kurekebisha viwango vya darasa la kwanza, bei ya stempu haipaswi kuongezeka kwa senti 17.  <response>: Moreover, unless the Postal Service is incapable of shedding volume variable costs or waits until 2008 before adjusting First--Class rates, the price of a stamp does not have to go up by 17 cents. 