The worldwide production of information has increased by 30 per cent each year between 1999 and 2002, according to researchers at the University of California, Berkeley.
The team started measurements with terabytes, but quickly found that insufficient; they also measured information by exabytes, each equal to a million terabytes.
In 2002, we produced about five exabytes of information on paper, film, optical and magnetic media, equal to about half a million new libraries, each containing a digitized version of the print collection of the U.S. Library of Congress. This was twice the volume produced in 1999.
The telephone accounts for the largest percentage of information flow, with e-mail (including spam) placing second.