Why do all dutch crime statistics go by "suspects" and not convictions

https://www.cbs.nl/nl-nl/achtergrond/2016/47/criminaliteit

Can someone explain this to me. Was discussing the crime rate in Netherlands with some friends but everything that is available seems to be "suspects" of crime and not convictions? Why is that? In other countries the statistics are always by convictions and not by suspects. What use is crime rate by suspects when its not even confirmed they are guilty. I dont understand this