skill set vs virtuosity

skill set

noun
  • A set of skills. 

  • The skills needed to accomplish a specified task or perform a given function. 

virtuosity

noun
  • The technical skills and fluent style of a virtuoso. 

  • Lovers of the elegant arts as a class. 

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