How many yards difference was Donovan McNabb's first touchdown pass compared to his last?
return Donovan McNabb ;return touchdown passes of #1 ;return the  first of #2 ;return the  last of #2 ;return the  yards of #3 ;return the  yards of #4 ;return the  difference of #5 and  #6
['select', 'project', 'aggregate', 'aggregate', 'project', 'project', 'arithmetic']