anchoress vs sadhu

anchoress

noun
  • A female anchorite. A woman who chooses to withdraw from the world to live a solitary life of prayer and contemplation. 

  • An anchorwoman. 

sadhu

noun
  • An ascetic or practitioner of yoga (yogi) who has given up pursuit of the first three Hindu goals of life: kama (enjoyment), artha (practical objectives) and even dharma (duty). 

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