<prompt> Translate the following text to EnglishKwa kuongezea, akiba ya kitaifa inaweza kutofautiana kati ya nchi kwa sababu ya tofauti katika bei ya bidhaa za mtaji, viwango vya mapato, viwango vya ukuaji, sera za kiuchumi na kijamii, idadi ya watu, na hata utamaduni.  <response>: In addition, national saving may vary across countries due to differences in the price of capital goods, income levels, growth rates, economic and social policies, demographics, and even culture. 