aerialist vs sadhu

aerialist

noun
  • A specialist in aerials, a freestyle skiing discipline. 

  • An acrobat performing high off the ground, defying a fall to earth, as on a trapeze or a tightrope. 

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 aerialist and sadhu occurred in a corpus of books? (source: Google Ngram Viewer )