forgo vs leave alone

forgo

verb
  • To refrain from, to abstain from, to pass up, to withgo. 

  • To let pass, to leave alone, to let go. 

  • To do without, to abandon, to renounce. 

leave alone

verb
  • To desist or refrain from involvement with. 

  • To stop bothering (a person). 

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