latitude longitude - How do I convert ESRI X,Y to Lat, Long for Google Maps?

I've downloaded the data from NYC Parking regulation. I want to plot that on Google Maps. I use http://www.shpescape.com/ft/ to convert to Google Fusion Maps but the data is in X,Y coordinates instead of Lat, Long. How do I convert X,Y coordinates to Lat, Long? I'm using OSX.

Here's the sample data.

1005740.867110
243957.356623