imminent vs in the offing

imminent

adj
  • about to happen, occur, or take place very soon, especially of something which won't last long. 

in the offing

prep
  • Within the area of the sea known as the offing; at a considerable distance from land, but visible from shore, often in reference to an approaching ship. 

  • Soon to come; likely to happen; in the foreseeable future; projected to occur; on the horizon; in the wind. 

  • At a distance, but visible. 

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