How many more percentage votes did Barack Obama receive from New Jersey than Mitt Romney?
return Barack Obama ;return Mitt Romney ;return New Jersey votes of #1 ;return New Jersey votes of #2 ;return percentage of #3 ;return percentage of #4 ;return the  difference of #5 and  #6
['select', 'select', 'project', 'project', 'project', 'project', 'arithmetic']