dirty pillow vs tract of land

dirty pillow

noun

  • A breast, especially a woman's breast. 

  • Used other than figuratively or idiomatically: see dirty, pillow. 

tract of land

noun

  • A woman's breast. 

  • Used other than figuratively or idiomatically: see tract, of, land. 

How often have the words dirty pillow and tract of land occurred in a corpus of books? (source: Google Ngram Viewer )