This example shows an annual house price index from 2000 to 2010, highlighting a sharp rise in prices through 2006 followed by a decline. A blue-to-cyan linear gradient fills the area under the line, created with `d3.area()`. The visualization uses `d3.scalePoint()` for the year axis and `d3.scaleLinear()` for the price axis, with axes generated by `d3.axisBottom()` and `d3.axisLeft()`. The SVG chart is rendered with D3 v7.