bahaha vs heh

bahaha

intj
  • Representation of laughter. 

heh

intj
  • Weak amusement, sometimes signaling boredom. 

noun
  • The fifth letter of many Semitic alphabets (Phoenician, Aramaic, Hebrew, Syriac, Arabic and others). 

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