ettle vs put one's back into

ettle

verb
  • To aim; purpose; intend; attempt; try. 

  • To make attempt. 

  • To take aim. 

  • To expect; reckon; count on. 

  • To direct one's course. 

  • To aspire; be ambitious. 

noun
  • Intention; intent; aim. 

put one's back into

verb
  • Synonym of strive: to apply oneself. 

How often have the words ettle and put one's back into occurred in a corpus of books? (source: Google Ngram Viewer )