Use arrays.
var data = [2000, 75, 840, 28500, 2000000, 7.50];
for(var i = 0; i < data.length; i++)
console.log(5 / 100.0 * data[i]);
If you don’t want values to be index based you can use objects as well.
var data = {
a: 2000,
b: 75,
c: 840,
d: 28500,
e: 2000000,
f: 7.50,
};
for(var key in data)
console.log(5 / 100.0 * data[key]);