How many more copies of the Hobbit sold in 2002 and 2003 than 2000 and 2001?
return the  Hobbit ;return copies of #1 sold ;return #2 in  2002 ;return #2 in  2003 ;return #2 in  2000 ;return #2 in  2001 ;return number of  #3 ;return number of  #4 ;return number of  #5 ;return number of  #6 ;return sum of #7 and  #8 ;return sum of #9 and  #10 ;return difference of #11 and  #12
['select', 'project', 'filter', 'filter', 'filter', 'filter', 'aggregate', 'aggregate', 'aggregate', 'aggregate', 'arithmetic', 'arithmetic', 'arithmetic']