Sufi vs hikikomori

Sufi

noun
  • A mystic Muslim; a Muslim ascetic; a practitioner of Sufism. 

hikikomori

noun
  • A Japanese phenomenon whereby an individual becomes a recluse from society, typically remaining isolated in a single room at home for a very long period. 

  • A reclusive person of this kind. 

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