ballot vs voting slip

ballot

noun
  • Originally, a small ball placed in a container to cast a vote; now, by extension, a piece of paper or card used for this purpose, or some other means used to signify a vote. 

  • The process of voting, especially in secret; a round of voting. 

  • The total of all the votes cast in an election. 

  • A list of candidates running for office; a ticket. 

verb
  • To draw lots. 

  • To vote or decide by ballot. 

voting slip

noun
  • a piece of paper with a list of the candidates at an election (sometimes with an indication of the candidate's party); the voter puts an X in the corresponding place against the candidate of his choice, folds the slip and places it in a ballot box provided. 

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