community service vs volunteering

community service

noun
  • Service or activity done for the benefit of the community at large, such as cleaning, fundraising, pro bono professional services, etc. 

  • Such work done as alternative for a criminal penalty. 

volunteering

noun
  • The act of voluntarily giving time and labor for charity or community service. 

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