How many fewer H-1B visas were issued in 2010 than in 2011?
return H-1B visas ;return #1 issued in  2010 ;return #1 issued in  2011 ;return number of  #2 ;return number of  #3 ;return difference of #5 and  #4
['select', 'filter', 'filter', 'aggregate', 'aggregate', 'arithmetic']