mind-numbing vs soul-destroying

mind-numbing

adj
  • Excessively boring, tedious, or dull; repetitive; of an activity, etc., lacking any interest or variety that might serve as intellectual stimulation. 

soul-destroying

adj
  • Causing erosion of moral fortitude or that eliminates hope or motivation 

How often have the words mind-numbing and soul-destroying occurred in a corpus of books? (source: Google Ngram Viewer )