Calculate the percentage of an object property

I have an object, where i want to calculate the percentage and display in the maps, currently the data i am getting is a raw data in an object.

Here is the object that i am receiving from backend

          [{
            "date": "26/08/2021",
            "walking": 965.2107,
            "running": 964.0539,
            "sleeping": 962.1473,
            "swimming": 961.8081,
            "studying": 961.5081,
          }]

Based on the object i want the percentage to be calculated and replaced in the respective key/value pair. It will take the object value, sum it up and calculate the percentage. This is what i am expecting to return

          [{
            "date": "26/08/2021",
            "walking": 20,
            "running": 20,
            "sleeping": 20,
            "swimming": 20,
            "studying": 20,
          }]

Answer

const data = [{
  "date": "26/08/2021",
  "walking": 965.2107,
  "running": 964.0539,
  "sleeping": 962.1473,
  "swimming": 961.8081,
  "studying": 961.5081,
}];

const dataInPerCents = data.map(item => {
  const itemCopy = {...item};
  const keys = Object.keys(itemCopy).filter(key => key !== "date");
  const sum = keys.reduce((sum, key) => sum + itemCopy[key], 0);
  keys.forEach(key => itemCopy[key] = Math.round(100 * itemCopy[key] / sum));
  itemCopy.top3 = keys.sort((key1, key2) => item[key2] - item[key1]).slice(0, 3); // Asked in comment below
  return itemCopy;
});
console.log(dataInPerCents);