become of vs come about

become of

verb
  • to happen to, to occur to. 

come about

verb
  • To come to pass; to develop; to occur; to take place; to happen; to exist. 

  • To tack; to change tack; to maneuver the bow of a sailing vessel across the wind so that the wind changes from one side of the vessel to the other; to position a boat with respect to the wind after tacking. See also come to. 

  • To change; to come round. 

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