cool cat vs iceberg

cool cat

noun
  • An individual who is at ease and self-assured; one who is calm and composed in interactions with others. 

  • A person who performs or appreciates jazz, especially one whose style of speech and movement is relaxed and rhythmic. 

iceberg

noun
  • An aloof person. 

  • A huge mass of ocean-floating ice which has broken off a glacier or ice shelf 

  • An impending disastrous event whose adverse effects are only beginning to show, in reference to one-tenth of the volume of an iceberg being visible above water. 

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