no end to vs perpetual

no end to

perpetual

adj
  • Set up to be in effect or have tenure for an unlimited duration. 

  • Continuing; uninterrupted. 

  • Lasting forever, or for an indefinitely long time. 

  • Flowering throughout the growing season. 

How often have the words no end to and perpetual occurred in a corpus of books? (source: Google Ngram Viewer )