Once the division concludes, the tellers provide the results to the presiding officer, who then announces them to the house. If the votes are tied, the Speaker or Deputy Speaker has a casting vote. Traditionally, this casting vote is exercised to allow further debate, if this is possible, or otherwise to avoid a decision without a majority (e.g. voting 'No' to a motion or the third reading of a bill). Ties rarely occur: more than 25 years passed between the last two ones in July 1993 and April 2019. The quorum of the House of Commons is 40 members for any vote, including the Speaker and four tellers. If fewer than 40 members have participated, the division is invalid.