erratic vs sane

erratic

adj
  • Deviating from normal opinions or actions; eccentric; odd. 

  • Unsteady, random; prone to unexpected changes; not consistent. 

noun
  • A rock moved from one location to another, usually by a glacier. 

  • Anything that has erratic characteristics. 

sane

adj
  • Being in a healthy condition; not deranged; thinking rationally. 

  • Mentally sound; possessing a rational mind; having the mental faculties in such condition as to be able to anticipate and judge the effect of one's actions in an ordinary manner. 

  • Rational; reasonable; sensible. 

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