What is referred to by '13 plus 14'?

Based on the clue '13 of scotlands caledonian canal is manmade the re...', what is the answer? Based on the clue '13 of the 39 men whove held this job were born in ...', what is the answer? Based on the clue '13 of the new testaments 27 books are attributed t...', what is the answer? Based on the clue '13 of the people in this south american country li...', what is the answer? Based on the clue '13 popes have been innocent 14 have been this mean...', what is the answer? Based on the clue '13 the size of us this royal kingdom has no rivers...', what is the answer? Based on the clue '13 to the guy who makes your bread', what is the answer? What is referred to by '13 witches'?