afforestation vs reforestation

afforestation

noun
  • The act or process of creating a new forest where none had existed before, or reforestation of areas long deforested. 

reforestation

noun
  • The act or process of replanting a forest, especially after clear-cutting. 

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