data = Object.assign((d3.csvParse(await FileAttachment("BrkSp500@3.csv").text(), d3.autoType)).map(({Year, Brk_gain, Brk_price, SP500_gain, SP500_price}) => ({index: Year, y1: Brk_price, y2:SP500_price, y1_gain:Brk_gain, y2_gain:SP500_gain})), {x: "Year", y1: "BRK.A", y2:"SP500"})