completion vs downtime

completion

noun
  • The act or state of being or making something complete; conclusion, accomplishment. 

  • The space resulting from such an act. 

  • The conclusion of an act of conveyancing concerning the sale of a property. 

  • The act of making a metric space complete by adding points. 

  • A forward pass that is successfully caught by the intended receiver. 

downtime

noun
  • The amount of time lost due to forces beyond one's control, as with a computer crash. 

  • A period of time set aside for rest and relaxation; leisure time. 

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