Many tasks related to the enactment, interpretation, and application of laws require examining not only the current version of a statute but also its previous versions. For example, existing Finnish online legal databases provide little support for user-friendly comparison of different versions of the same statute. This paper presents a solution for modelling and visualising statute change histories, enabling easier tracking and interpretation of legislative changes over time. A new prototype application Statute History  is introduced to use statutory history data in legal decision making. This application is based on extending an existing Knowledge Graph (KG) (Semantic Finlex) and embedding the prototype into an existing open source User Interface (UI) of a legal web service (LawSampo). Although Finnish legislation is used as a case study, the methods and software presented can arguably also be applied in other countries with a similar legislation system. Statute History  enables comparison of different versions of statutes and easy access to related preparatory works. To evaluate the application, a user survey with legal experts was conducted. The respondents found the prototype a clear improvement over existing services, although also identified needs for finer-grained change tracking and more intuitive visual design. User-friendly tracking of statute change history and effortless retrieval of associated preparatory works was deemed essential for legal professionals.