peculiar vs rare as hen's teeth

peculiar

adj
  • Out of the ordinary; odd; strange; unusual. 

  • Common or usual for a certain place or circumstance; specific or particular. 

noun
  • an ecclesiastical district, parish, chapel or church outside the jurisdiction of the bishop of the diocese in which it is situated. 

  • That which is peculiar; a sole or exclusive property; a prerogative; a characteristic. 

rare as hen's teeth

adj
  • extremely uncommon 

How often have the words peculiar and rare as hen's teeth occurred in a corpus of books? (source: Google Ngram Viewer )