Question Wording

I really like the idea of asking about which elections people voted in. Wording-wise I would put it something more like:

Which of the following BC elections have you voted in? a. 1997 b.2001 c.2005 d.2009 e. None of the above

I think giving the option of 'none of the above' is a good idea since it would separate people who choose not to answer and people who haven't voted.