Which group in percent of commuters in Dallas in 2009 is smaller: carpooling or walking?
return commuters in   Dallas in  2009 ;return #1 that are carpooling commuters ;return #1 that are walking commuters ;return percent of #2 ;return percent of #3 ;return which is the  lowest of #4 ,  #5
['select', 'filter', 'filter', 'project', 'project', 'comparison']