phylum vs regnum

phylum

noun
  • A rank in the classification of organisms, below kingdom and above class; also called a divisio or a division, especially in describing plants; a taxon at that rank 

  • A large division of possibly related languages, or a major language family which is not subordinate to another. 

regnum

noun
  • A rank in the classification of organisms, below dominium and above divisio. 

  • A badge of royalty, especially the early form of the pope's tiara. 

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