haulier vs schlepper

haulier

noun
  • A person or company engaged in the haulage of goods. 

  • A miner who hauls coal from the coalface to the bottom of the shaft. 

schlepper

noun
  • A servant who carries things; a porter. 

  • Any manual laborer, or other lowly employee. 

  • One who wanders aimlessly. 

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