<prompt> Translate the following text to EnglishKwa mujibu wa viwango vya kihistoria vya Marekani, uhifadhi wa jumla wa kitaifa wa Marekani umekuwa chini kuliko nchi nyingine kubwa za viwanda katika miongo minne iliyopita tazama mchoro 2.3.  <response>: U.S. historical standards, U.S. gross national saving has generally been lower than other major industrialized countries over the past 4 decades see figure 2.3. 