flotation vs initiation

flotation

noun
  • A state of floating, or being afloat. 

  • The ability (as of a tire or snowshoes) to stay on the surface of soft ground or snow. 

  • A process of separating minerals by agitating a mixture with water and detergents etc; selected substances being carried to the surface in air bubbles. 

  • The launching onto the market of a tranche of stocks or shares, usually a new issue. 

initiation

noun
  • The act of initiating, or the process of being initiated or introduced 

  • The first step of transcription or of transduction. 

  • The form or ceremony by which a person is introduced into any society; mode of entrance into an organized body; especially, the rite of admission into a secret society or order. 

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