heirship vs tradition

heirship

noun
  • The status of being heir to something or someone 

tradition

noun
  • A part of culture that is passed from person to person or generation to generation, possibly differing in detail from family to family, such as the way to celebrate holidays. 

  • The act of delivering into the hands of another; delivery. 

  • An established or distinctive style or method 

  • A commonly held system. 

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