by Maurice Y. Michaud (he/him)
From the beginning of Confederation until today, there have been a total of 3,188 by-elections at the federal and provincial or territorial level. Of that number, the data is missing from only 253 events (7.94%) — principally from Ontario and Prince Edward Island. You can request to include by-election results when exploring the "Detailed election results" subsection, or you can find them here. It's your choice!