currency vs pork barrel

currency

noun
  • Money or other items used to facilitate transactions. 

  • The state of being current; general acceptance or recognition. 

  • Paper money. 

pork barrel

noun
  • State funds as assigned for local or regional expenditure; especially, central money used for regional projects which are eyecatching or designed to appeal to voters. 

  • A ready supply of income; one's livelihood. 

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