Do the 50% who do claim they are victims of theft say it only happened to them a single time? In my experience, the people who admit they are the victims of theft have countless stories of it happening to them.
> In my experience, the people who admit...
Again, one person's anecdote is not a reliable way of measuring these things.
I would suspect that people who have been a victim of theft once are much more likely to be a victim again.