bigender vs cisgender

bigender

adj
  • Having two genders simultaneously: both male and female. 

  • Having a tendency to move between feminine and masculine gender-typed behaviour depending on context. 

cisgender

adj
  • Having a gender identity which matches the sex one was assigned at birth; or, pertaining to such people. 

noun
  • A cisgender person. 

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