taxicab vs tro tro

taxicab

noun
  • a vehicle that passengers hire to take them between locations of their choice, the fare being calculated with a taximeter; a taxi or cab 

verb
  • To travel by taxicab. 

tro tro

noun
  • A minibus operating as a share taxi in Ghana. 

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