multitudinous vs piles of

multitudinous

adj
  • Crowded with many people. 

  • Coming from or produced by a large number of beings or objects. 

  • Existing in great numbers; innumerable. 

  • Comprising a large number of parts. 

piles of

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