blurred vs clouded

blurred

adj
  • Out of focus; partially obscured; smudged. 

clouded

adj
  • Made dim or blurry. 

  • Variegated with spots. 

  • Filled with clouds. 

  • Unclear; surrounded in mystery. 

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