limerick vs rhyming

limerick

noun
  • A humorous, often bawdy verse of five anapaestic lines, with the rhyme scheme aabba, and typically having an 8–8–5–5–8 cadence. 

rhyming

noun
  • rhyme 

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