Extra police were hired and vehicles in known areas of street work placed under surveillance. Ninety-one reports were filed in 1999, and a reduction in visible prostitution was noted while acknowledging that estimating the actual activity of prostitution was extremely difficult, and that it was quite possible it had merely gone underground. The difficulties of enforcement were immediately noted by the police who had opposed the law, and the difficulty in getting a conviction was even harder under Swedish judicial procedure and the rights of citizens. Few of the reports in 1999 were concluded. Six convictions were obtained, and fines imposed. Difficulties in even understanding the law were noted, and understandably prostitutes were reluctant to inform or testify against their clients. The Socialstyrelsen (National Board of Health and Welfare) noted that estimating the extent of prostitution was almost impossible. A number of reports suggest that prostitution was at a low level in Sweden, and was on the decline, but may have experienced a slight increase in the 1990s.