Highchart: sankey how to calculate percentage for the last column

Question

I am calculation with percentage as shown but failing in last column:

https://codepen.io/soureshcoumar/pen/ZExOmbV

nodeFormatter() {
          const { point } = this;
          const percentage = point.linksTo[0]
            ? (point.sum / point.linksTo[0].fromNode.sum) * 100
            : point.linksFrom[0]
            ? (point.sum / point.linksFrom[0].toNode.sum) * 100
            : console.log(node)

          return `<span style="font-color: black; line-height: 18px; letter-spacing: 0px; font-size: 13px;">${
            point.name
          }</span><br><span style="font-weight: 400; line-height: 15px; letter-spacing: 0px; font-size: 11px;">$${
            point.sum
          }K</span>&nbsp;&nbsp;${Math.round(
            percentage,
          )}%</span>`;
        }