How many years was Baillie professor of divinity in Glasgow University before being made principal?
return Baillie was  professor of divinity in  Glasgow University ;return Baillie was  made principal ;return years of #1 ;return year of #2 ;return the  lowest of #3 ;return the  difference of #4 and  #5
['select', 'select', 'project', 'project', 'aggregate', 'arithmetic']