In the 2000 U.S. Census  which was the lowest category, households or families?
return 2000 U.S. Census ;return households of #1 ;return families of #1 ;return number of  #2 ;return number of  #3 ;return which is lowest of #4 ,  #5
['select', 'project', 'project', 'aggregate', 'aggregate', 'comparison']