<prompt> Translate the following text to EnglishSehemu ya ongezeko la akiba ya kitaifa inayotumiwa kwa uwekezaji wa ndani huongeza hisa za mtaji zinazopatikana kwa wafanyakazi kuzalisha bidhaa na huduma nchini Marekani.  <response>: The portion of an increase in national saving used for domestic investment adds to the capital stock available for workers to produce goods and services in the United States GDP. 