regain (possession of) vs win back

regain (possession of)

win back

verb
  • To get (someone) to be one's partner, after having been apart. 

  • To win (something) that one has previously lost. 

  • To regain favour (with). 

How often have the words regain (possession of) and win back occurred in a corpus of books? (source: Google Ngram Viewer )