An ascertained crime is an event, which after the completion of preparatory proceedings was confirmed as a crime. In connection with the Criminal Code of 1997 coming into force on 1 IX 1998 (the Law dated 6 VI 1997, Journal of Laws No. 88, item 553, with later amendments) crime is a felony or misdemeanour prosecuted upon by public accusation or private accusation by public prosecutor, moreover every revenue-related misdemeanour, the character of which was confirmed as a crime as a result of preparatory proceedings. Information regarding ascertained crimes and rates of detectability of delinquents in ascertained crimes has been prepared on the basis of the police statistics, supplemented with information on investigations conducted by the public prosecutors` offices and on juvenile proceedings in family courts. Data on ascertained crimes have been prepared in accordance with the classification of the Criminal Code of 1997, the Treasury Penal Code (the Law dated 10 IX 1999, Journal of Laws No. 83, item 930) or other specific laws. The rate of detectability of delinquents is the relation of the number of detected crimes in a given year (including those detected after resumption following discontinuance) to the total number of crimes ascertained in a given year, plus the number of crimes recorded in commenced proceedings and discontinued in previous years due to undetected delinquents. Since 2013, all data are calculated excluding statistical information on their own investigations of prosecutor and investigations assigned to conduct the authorized agencies other than the police, as well as with limited information about the activities of juvenile offenses and therefore are not fully comparable with the rates from previous years.