aggregation vs subspecies

aggregation

noun
  • A collection of particulars; an aggregate. 

  • The state of being collected into a mass, assemblage, or sum (aggregated). 

  • Summarizing multiple routes into one route. 

  • The act of collecting together (aggregating). 

  • The majority of the parasite population concentrated into a minority of the host population. 

  • Kind of object composition which does not imply ownership. 

subspecies

noun
  • A subdivision of a species in other scientific disciplines. 

  • A taxon at that rank, often indicated with trinomial nomenclature (such as Felis silvestris silvestris in zoology and Pinus nigra subsp. salzmannii in botany). 

  • A rank in the classification of organisms, below species. 

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