Re: data growth- information growth- usage stats
One way to judge the increase in data can be to see how much the price has gone down on Data storage hardware. For a regular PC one can buy an external hard drive of over 100 GB in less than 50$, five years ago you couldnt even think about buying anywhere near half of this much space for this price.
If Data Storage hardware price for personal usage has gone down then i am sure trend would be similar for companies/organizations that buy more data storage hardware than common person.