Line chart ice 7
This chart displays the average fuel efficiency, measured in miles per gallon, for vehicles across different model years, spanning from 1970 to 1982. The data is aggregated by year, with each point representing the mean MPG for that year, and the line connects these points to show the overall trend. Built using D3 v7, the visualization uses `csv` for data loading, `rollup` and `mean` for aggregation, and `scaleLinear`, `axisBottom`, and `axisLeft` for axes and gridlines. The `line` generator draws the path, while `join` appends circles for each data point. The data comes from a gist CSV file.