<prompt> Translate the following text to EnglishKiwango hiki cha uingizwaji kinategemea kutumia sheria za faida za usalama wa kijamii kwa wafanyakazi wa kustaafu wa miaka 65 katika 2001 ambao walikuwa na viwango vya mapato ya kudumu katika kazi zao.  <response>: These replacement rates are based on applying Social Security benefit rules to hypothetical retired workers age 65 in 2001 who had steady earning levels over their careers. 