Spiritual vs abbot

Spiritual

noun
  • A member of a branch of the Franciscan order that advocated simple dress and renounced the owning of property. 

abbot

noun
  • The superior or head of an abbey or monastery. 

  • The pastor or administrator of an order, including minor and major orders starting with the minor order of porter. 

  • A layman who received the abbey's revenues, after the closing of the monasteries. 

How often have the words Spiritual and abbot occurred in a corpus of books? (source: Google Ngram Viewer )