I'm currently filing out the immigration paperwork and one question has me stumped. It's asking for dates, length of stay etc for the times I visited. The problem is that being that I'm from Detroit and my wife is from Windsor, I've visited very often the last 4.5 years. Well over 150-200 different times, so i dont remember how long i stayed or the length for each visit and the only receipts I have are toll transactions on my debit card from maybe 2 years back. What's a resolution to this problem? Thank you