How many more aimag general hospitals is the health sector comprised of than specialized hospitals and centers ?
return the  health sector ;return aimag hospitals in  #1 ;return specialized hospitals in  #1 ;return centers in  #1 ;return number of  #2 ;return number of  #3 ;return number of  #4 ;return sum of #6 and  #7 ;return difference of #5 and  #8
['select', 'project', 'project', 'project', 'aggregate', 'aggregate', 'aggregate', 'arithmetic', 'arithmetic']