This Sankey diagram visualizes the flow of German voters between political parties from 2015 to 2017, tracking changes in party affiliation, non-voting, and demographic shifts. The visualization uses D3.js version 3 with a custom sankey.js library to render the diagram as scalable vector graphics, with nodes representing party affiliations and links showing the volume of voter movement. The code reads data from a CSV file, processes the node and link relationships, and generates a web-based interactive visualization.