censorship vs erasement

censorship

noun
  • The use of state or group power to control freedom of expression or press, such as passing laws to prevent media from being published or propagated. 

  • The role of the censor (magistrate) in Ancient Rome. 

erasement

noun
  • erasure; obliteration 

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