backpacking vs hiking

backpacking

noun
  • hiking and camping overnight in backcountry with one's gear carried in a backpack. 

  • low-cost, generally urban, travel with minimal luggage and frugal accommodations. 

hiking

noun
  • Walking in the countryside for pleasure or sport. 

  • The act by which something is hiked, or raised sharply. 

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