Why the discrepancy? Maybe it's geographic as the other commenters suggests. The Netherlands is in the middle of somewhere while New Zealand is in the middle of nowhere. That sounds plausible to me. I think it might also be cultural. The Netherlands is known around the world for their sex industry, New Zealand is not. This makes the Netherlands a more rational destination for profit seeking predators.
In some places, it's not merely a theory.
Why the discrepancy? Maybe it's geographic as the other commenters suggests. The Netherlands is in the middle of somewhere while New Zealand is in the middle of nowhere. That sounds plausible to me. I think it might also be cultural. The Netherlands is known around the world for their sex industry, New Zealand is not. This makes the Netherlands a more rational destination for profit seeking predators.