<prompt> Translate the following text to SwahiliThe 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.  <response>: Sehemu ya ongezeko la akiba ya kitaifa inayotumiwa kwa uwekezaji wa ndani huongeza hisa za mtaji zinazopatikana kwa wafanyakazi kuzalisha bidhaa na huduma nchini Marekani. 