If I calculated correctly, the 75th percentile is about 43k in euro's. That's quite a bit below market for the Netherlands, but does not take cost of living into account.
I wouldn't say it is quite below the average. One of the things about Netherlands is that it really depends upon the city you live in. If you are not in Amsterdam, it is a different story.
I'd say they definitely earn more money than their folks in south Europe (Spain, Portugal, Italy and Greece)