My opinion not founded on statistics but observation is that many people who claim to be abused by NPD people are actually dealing with narcissistic tendencies rather than a wholly diagnosed person.

The behaviors in my ex came across in some areas as being narcissistic..but researching farther what I realized actually were his behaviors have some areas that look very similar to the way a narcissist would react but the foundation of the behavior was totally different than NPD.

Many people only look at one possibility & stick that label on without actually researching farther.....& in reality everyone has some tendency at one time or another in their REACTIONS to respond in a narcissistic way especially when they feel the need to defend themself against something but in reality are as far from being NPD as night is from day.