philia vs soft spot

philia

noun
  • liking 

  • a psychological disorder characterized by an irrational favorable disposition towards something 

  • friendship 

soft spot

noun
  • A sentimental fondness or affection. 

  • A point of vulnerability in a defence. 

  • A fontanelle. 

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