How to I parse and Display JSON data from event in a report

# I was fiddling around with this dashboard!

I have a test report created in which I want to display the current value of USD-INR.
My event data looks like this:

``` javascript
[
  {
    "type": "usd",
    "date": 1473142784,
    "properties": {
      "rate": 66.79
    }
  }
]
```

How do I extract the rate value and display it?
