Nigger vs Sango

Nigger

name
  • Niger (country). 

  • A given name for a black pet. 

Sango

name
  • The primary language spoken in the Central African Republic: it has 5 million second-language speakers, but only 400,000 native speakers, mainly in the towns. 

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