title: Does the Nest API provide a way to get historical energy usage?
body: <p>Ever since I got my Nest all I've wanted is to be able to aggregate my energy usage over a long period of time to look for patterns and mainly appease my curiosity.  Sure there are the monthly usage reports, and the web and device only goes back 10 days.  </p>
  
  <p>Does the API expose that data, or would I need to somehow calculate it myself?  I'm not seeing on the API reference anything like 'is_running'.  Or is there a chance a future "Nest Data API" is going to come out?</p>