astern of vs in turn

astern of

prep
  • behind 

in turn

prep
  • In response; in return. 

  • One after the other; one at a time; in succession; successively. 

  • Having a relationship sequentially comparable to one just mentioned; accordingly or similarly, with respect to sequence, precedence, or hierarchy. 

  • In due order; in proper sequence; in a determined or measured sequence, as a waiting line or queue. 

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