question: Which country has the highest elderly population, 12 % in United States or 21.2% in Japan?
#1 return the  United States 
#2 return Japan 
#3 return the  elderly population of #1 
#4 return the  elderly population of #2 
#5 return %  of #3 
#6 return %  of #4 
#7 return which is the  highest of #5 ,  #6