semi-professional vs semipro

semi-professional

noun

  • a semi-professional sportsman or athlete 

adj

  • playing for pay on a part-time basis 

  • composed of semi-professional players 

semipro

noun

  • Semiprofessional. 

adj

  • Semiprofessional. 

How often have the words semi-professional and semipro occurred in a corpus of books? (source: Google Ngram Viewer )