acquire vs attain

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. 

attain

verb
  • To gain (an object or desired result). 

  • To reach or come to, by progression or motion; to arrive at (a place, time, state, etc.). 

  • To come or arrive, by motion, growth, bodily exertion, or efforts toward a place, object, state, etc. 

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