At a DAMP seminar I attended, statistics (I know, lies, damn lies & statistics) were used at one point to illustrate things. As best that I can recall them, when random testing was introduced in the US, the results were in the order of:
- 0.05% of pilots tested returned a positive result
- 0.5% of Cabin Crew tested returned a positive result
- 34% of security personnel tested returned a positive result