IOTA vs currency

IOTA

noun
  • A bank account that earns interest and pays it to a third party, generally a charity; the principal is typically being held in escrow by the accountholder. 

currency

noun
  • Money or other items used to facilitate transactions. 

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

  • Paper money. 

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