I bet the dutch central office of statistics keeps track of it. But then if you don't trust the one government body why should you trust another?

Personally I trust the dutch police force and in fact admire them greatly. They handle dangerous and stressful situations much better than I personally ever could. That said I do see why you'd be mistrustful as average citizen, the most you'll have to do with police is reporting crimes such as broken windows or stolen bikes, in which case you'll probably get a shrug and a "we'll look into it" at most.

The police force is currently very well trained and adequately supplied, but as is the story in many places budget cuts are being made all over and I worry for the future.

In any case an independent research office looking into the crime stats wouldn't be a bad thing, but I suspect it's a rather tricky thing to gauge in the first place.