dogface vs serviceman

dogface

noun
  • A foot soldier, especially during World War II. 

  • Either of two pierid butterflies of the New World genus Zerene. 

  • An ugly person. 

serviceman

noun
  • A man who serves in the armed forces. 

  • A person, especially a man, employed in service and maintenance of equipment. 

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