How many more volumes per year does the Main Library deal with compared to the growth of the Academic LIbrary 100 years prior?
return the  Main Library ;return the  Academic Library ;return volumes per year dealt with of #1 ;return growth in  volumes 100 years prior of #2 ;return the  difference of #3 and  #4
['select', 'select', 'project', 'project', 'arithmetic']