foster vs promote

foster

verb
  • To nurse or cherish something. 

  • To cultivate and grow something. 

  • To nurture or bring up offspring, or to provide similar parental care to an unrelated child. 

noun
  • A foster parent. 

  • The care given to another; guardianship. 

adj
  • Related by such care. 

  • Receiving such care. 

  • Providing parental care to children not related to oneself. 

promote

verb
  • To encourage, urge or incite. 

  • To increase the activity of (a catalyst) by changing its surface structure. 

  • To elevate to a higher league. 

  • To raise (someone) to a more important, responsible, or remunerative job or rank. 

  • To move on to a subsequent stage of education. 

  • To advocate or urge on behalf of (something or someone); to attempt to popularize or sell by means of advertising or publicity. 

  • To exchange (a pawn) for a queen or other piece when it reaches the eighth rank. 

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