accessible vs heavy-going

accessible

adj
  • Easily understood or appreciated. 

  • Capable of being used or seen. 

  • Easy to get along with. 

  • Open to the influence of. 

  • Obtainable; to be got at. 

  • Built or designed as to be usable by people with disabilities. 

  • Easy of access or approach. 

heavy-going

How often have the words accessible and heavy-going occurred in a corpus of books? (source: Google Ngram Viewer )