downpipe vs excavation

downpipe

noun
  • The drainpipe that connects a roof-line gutter with the ground. 

excavation

noun
  • The material dug out in making a channel or cavity. 

  • Archaeological research that unearths buildings, tombs and objects of historical value. 

  • The act of excavating, or of making hollow, by cutting, scooping, or digging out a part of a solid mass. 

  • An uncovered cutting in the earth, in distinction from a covered cutting or tunnel. 

  • A site where an archaeological exploration is being carried out. 

  • Something uncovered by archaeological excavation. 

  • A cavity formed by cutting, digging, or scooping. 

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