Unlike the majority of countries in Europe, crime data in Sweden is collected when the offence in question is first reported, at which point the classification may be unclear. In Sweden, once an act has been registered as rape, it retains this classification in the published crime statistics, even if later investigations indicate that no crime can be proven or if the offence must be given an alternative judicial classification.
Sweden also applies a system of expansive offence counts. Other countries may employ more restrictive methods of counting. The Swedish police registers one offence for each person raped, and if one and the same person has been raped on a number of occasions, one offence is counted for each occasion that can be specified. For example, if a woman says she has been raped by her husband every day during a year, the Swedish police may record more than 300 cases of rape. In many other countries only a single offence would be counted in such a situation.
In Sweden, crime statistics refer to the year when the offence was reported; the actual offence may have been committed long before. Swedish rape statistics can thus contain significant time-lag, which makes interpretations of annual changes difficult