Q. How do find industry data to show historical size & sales trends? I need the retail book industry from 1990-2007.
Try the database IBISWorld (go online to http://clients.ibisworld.com/launch.aspx?show=1 and find classification code 45121 under "retail trade").
In that database you will find a number of reports including "key statistics" which includes revenues from 2002 (actual) to 2016 (projected).