Helen vs Yelena

Helen

name

  • A female given name from Ancient Greek. 

  • the daughter of Zeus and Leda, considered to be the most beautiful woman in the world; her abduction by Paris brought about the Trojan War. 

noun

  • Any of various papilionid butterflies of the genus Papilio. 

Yelena

name

  • A transliteration of the Russian female given name Еле́на (Jeléna), equivalent to Helen. 

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