pushcart vs tricycle

pushcart

noun
  • A small cart, normally with two or four wheels, that can be pushed by hand. 

tricycle

noun
  • An autorickshaw; A motorized cycle rickshaw 

  • A cycle with three wheels, powered by pedals and usually intended for young children. 

verb
  • To ride a tricycle. 

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