Which country has the highest elderly population, 12 % in United States or 21.2% in Japan?
return the  United States ;return Japan ;return the  elderly population of #1 ;return the  elderly population of #2 ;return %  of #3 ;return %  of #4 ;return which is the  highest of #5 ,  #6
['select', 'select', 'project', 'project', 'project', 'project', 'comparison']