prosumer vs semiprofessional

prosumer

adj
  • Targeted at serious, enthusiastic consumers, incorporating professional features but often modified for non-professional use. 

  • high-end 

noun
  • A serious, enthusiastic consumer: not professional (earning money), but of similar interest and skills to a (generally lower level) professional, or aspiring to such. The target market of prosumer equipment. 

  • A person in postindustrial society who combines the economic roles of producer and consumer 

semiprofessional

adj
  • Of close to professional standard; prosumer. 

  • Of or pertaining to a semiprofession. 

  • Paid as a professional but on a part-time basis. 

noun
  • A semiprofessional person. 

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