How many more people were evicted in the 2012 incident compared to the 1991 incident?
return 2012 incident  ;return 1991 incident  ;return people evicted in  #1 ;return people evicted in  #2 ;return the  number of  #3 ;return the  number of  #4 ;return the  difference of #5 and  #6
['select', 'select', 'project', 'project', 'aggregate', 'aggregate', 'arithmetic']