contribution vs offertory

contribution

noun
  • An amount of money given toward something. 

  • Something given or offered that adds to a larger whole. 

  • The act of contributing. 

  • The taking part, often with the idea that it has led to (scientific etc.) progress. 

offertory

noun
  • The part of the Eucharist service when offerings of bread and wine are placed on the altar and when any collection is taken; also, the money or other things collected. 

  • A linen or silken cloth anciently used in various ceremonies connected with the administration of the Eucharist. 

  • A prayer said or sung as an anthem while offerings of bread and wine are placed on the altar during the Roman Catholic Mass or the Anglican Communion service. 

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