put on vs unlade

put on

verb
  • Used other than figuratively or idiomatically: see put, on. 

  • To assume, adopt or affect; to behave in a particular way as a pretense. 

  • To don (clothing, equipment, or the like). 

  • To initiate cooking or warming, especially on a stovetop. 

  • To perform for an audience. 

  • To organize a performance for an audience. 

  • To fool, kid, deceive. 

  • To bet on. 

  • To play (a recording). 

unlade

verb
  • To disburden; take the burden from; relieve. 

  • To discharge a cargo; discharge a burden. 

  • To discharge the cargo from. 

  • To unload. 

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