Wicca vs the black arts

Wicca

name
  • A neopagan religion that was first popularized by books written in 1949, 1954, and 1959 by Englishman Gerald Gardner, involving the worship of a horned male god and a moon goddess, the observance of eight Sabbats, and the performance of various rituals. 

the black arts

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