trekker vs yomp

trekker

noun
  • One who treks; a hiker. 

  • A person who spent the night in a rural area, rather than his home, during bombing raids. 

yomp

noun
  • A long-distance march carrying full kit. 

verb
  • To make a strenuous long-distance march. 

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