general election vs secret ballot

general election

noun
  • An election, usually held at regular intervals, in which candidates are elected in all or most constituencies or electoral districts of a nation. 

  • An erection. 

secret ballot

noun
  • The voting system involving ballots available only at official polling places, prepared at public expense, containing the names of all candidates, and marked in secret at the polling places. 

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