As of 2000, which group for households is larger: married couples living together or non-families?
return households in  2000 ;return #1 that are married couples living together ;return #1 that are non-families ;return number of  #2 ;return number of  #3 ;return which is more of #4 ,  #5
['select', 'filter', 'filter', 'aggregate', 'aggregate', 'comparison']