First of all, as I mentioned in my opening remarks, in 99% of the cases there evidently are no positive tests on the ion scan. Whatever positive tests there are, they will represent slightly less than 1% of the visitors who come into our institutions. Those are 2017 statistics. They were derived from the threat risk assessments conducted across the organization every time somebody hits positive—either when a detector dog handler detects something on a visitor or when there's a positive result on the ion scan.
From that information, in terms of the number of false positives, it becomes one of a number of items or elements that we consider when it's time for us to conduct our threat assessment.