acquire vs earn

acquire

verb
  • To gain, usually by one's own exertions; to get as one's own 

  • To sample signals and convert them into digital values. 

  • To contract. 

  • To get. 

earn

verb
  • To gain (success, reward, recognition) through applied effort or work. 

  • To cause (someone) to receive payment or reward. 

  • To achieve by being worthy of. 

  • To receive payment for work. 

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