accrue vs rack up

accrue

verb
  • To accumulate. 

  • To become an enforceable and permanent right. 

  • To increase, to rise 

  • To reach or come to by way of increase; to arise or spring up because of growth or result, especially as the produce of money lent. 

  • To be incurred as a result of the passage of time. 

rack up

verb
  • to gain (points etc.; in a game or sport), to accumulate 

  • to arrange in a rack 

  • to acquire, to gather together. 

  • to defeat severely, to thrash 

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