there are many different statistics available concerning the number of uninsured. here's one:

http://www.aflcio.org/aboutus/newsarchive/ns03102003.cfm

there is a wide range of insurance available to the employed, some health plans barely cover anything at all while others are Cadillac coverage. I've noticed smaller companies tend to have "bare bones" style coverages while the larger companies tend to have the Cadillac plans, but isn't always the case.