durable vs rocky

durable

noun
  • A durable thing, one useful over more than one period, especially a year. 

adj
  • Able to resist wear or decay; lasting; enduring. 

rocky

adj
  • In the style of rock music. 

  • Abounding in, or full of, rocks; consisting of rocks. 

  • Like a rock; rigid, solid. 

  • Having a habitat around or on rocks. 

  • Easily rocked; unstable. 

  • Encountering many problems; difficult, troubled; also, in danger or distress. 

  • Of a person: ill, or unsteady (for example, as a result of a shock). 

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