employed vs on the hop

employed

adj
  • Used; in use. 

  • In a job; working. 

on the hop

prep
  • Playing truant from school. 

  • Spontaneous; unplanned. 

  • Unprepared; unready and unable to deal with something. 

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