slackness vs soupiness

slackness

noun
  • The state of being slack; the quality of having slack. 

  • A subgenre of dancehall music with sexual lyrics. 

  • Vulgarity in West Indian culture. 

soupiness

noun
  • The state or condition of being soupy. 

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