Calculate percentages of loading time improvement

gistfile1.js

var times = [
  // Dashboard
  [12.50, 3.41],
  // Settings
  [12.04, 3.00],
  // Mention Stream
  [11.90, 3.07],
  [11.90, 4.35],
  // Signal Stream
  [11.81, 2.53],
  [11.81, 3.45]
]
var time, percent;
for (i in times) {
  time = times[i];
  percent = (time[0] - time[1]) / time[0] * 100;
  console.log(percent.toFixed(2));
}