bush taxi vs marshrutka

bush taxi

noun
  • A share taxi in parts of Africa. 

marshrutka

noun
  • A share taxi in the CIS countries, the Baltic states, and Bulgaria. The role of the modern marshrutka is similar to that of the minibus in other countries, except that some implementations of marshrutka allow passengers to stand. 

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