get rid of vs unlade

get rid of

verb
  • to rid oneself of; dispose (of); to remove; to abolish; to lose 

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 get rid of and unlade occurred in a corpus of books? (source: Google Ngram Viewer )