When I started working full time in 1988 the top man in the company, in charge of 25,000 staff, earned approx 15 times the hourly rate of the lowest paid employee. I know this because it was published in the annual financial report, which the company handed to the union for checking, and it was then distributed to staff.
In contrast, the company I now work for is a lot more shady about finances. Senior executives are compensated via trusts, and a lot of our income is from top secret US military projects that are not funded directly by government, so the figures cannot be released.
As luck would have it though, our top man is listed in the Forbes rich list, and from the data there I can tell you his annual compensation for 2009, including pension payments and share options, was almost exactly 1,000x my salary for that year.