approval vs props

approval

noun
  • An expression of favorable acceptance and encouragement; a compliment that also condones. 

  • Something mailed by a seller to a collector to match their stated interests; the collector can approve of or return the item. 

  • An expression granting permission; an indication of agreement with a proposal; an acknowledgement that a person, thing, or event meets requirements. 

props

noun
  • Respect for, or recognition of, another person; an expression of approval or a special acknowledgment; accolades; praise. 

intj
  • An acclamation of respect or recognition. 

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