NEW YORK (CNN/Money) - The Equal Employment Opportunity Commission collected a record $420 million from employers that violated workplace discrimination laws even as the total number of complaints filed dropped for the second consecutive year.

According to a year-end report released Tuesday, in 2004 employees filed approximately 79,400 complaints with the EEOC, the federal agency charged with protecting workers against job discrimination. That's nearly 2,000 fewer complaints than were filed in 2003 and 5,000 less than in 2002.

Of the $420 million collected in 2004, $168 million came from lawsuits and the remainder from pre-litigation settlements or fines.

The range of complaints tracked include race, sex, age, and disability discrimination.

Since 1992, the earliest year for which data is available on the agency's Web site, the number of complaints filed have seesawed, with the 91,200 complaints filed in 1994 representing a peak year. The levels dropped significantly throughout the late 1990s boom years and then started to creep back up starting in 2000, when the economy soured.

Conventional wisdom holds that the volume of employment cases rises as more people lose their jobs in a bad economy and falls when times are good.

"In a down economy, when people are let go from their jobs and they are unable to walk across the street and get another job immediately, there's a much greater chance they're going to be angry and upset," explained Michael Delikat, a New York employment lawyer and partner in Orrick, Herrington & Sutcliffe.

"If (workers) lose their jobs when the economy is strong, they're more likely to say 'I can go across the street and make more money than I did at the other (place), let's not live in the past. Let's look ahead," said Delikat.

Indeed, after climbing up to 84,400 complaints in 2002, the numbers have declined in each of the last two years.

As in past years, the most common discrimination charges in 2004 centered on race, sex and retaliation. Retaliation claims, in which workers claim they were punished for notifying supervisors of sex harassment or some other workplace violation, are often pooled with other discrimination claims.

Except for a small uptick in retaliation charges, all categories of discrimination tracked by the EEOC posted declines in 2004.

There are limits, however, to what those numbers signal about workplace disputes generally. Workers are required to file an EEOC complaint before they can sue an employer in federal court. But that's not the case for state court cases, which the EEOC does not track. Nor do the figures cover payments employers make to resolve cases privately before they wind up in court.

"It's hard to draw any definite conclusions (from the EEOC numbers)," said Delikat. "Does (the drop) mean that people feel there's less discrimination going on in the workplace? Not necessarily."

Take, for instance, age discrimination claims. EEOC complaints by older workers saw the biggest drop in 2004. At about 17,800, filings were down nearly 7 percent from 2003.

At the same time, the number of age-related complaints that then triggered an EEOC lawsuit nearly doubled in 2004, to 40. In one high-profile case, the agency last month sued the Chicago law firm of Sidley Austin Brown & Wood on behalf of at least 31 older partners who were forced to retire or demoted.

The agency's pursuit of age-related lawsuits indicates that the treatment of older workers is a big concern, said Delikat.

"What most employers in this day and age fear most is the age discrimination lawsuit," he said. Unlike race or gender claims, age-related charges resonate with every potential juror. "It's the hardest (accusation) to defend usually."

Fortune 500 companies facing age discrimination lawsuits include Sprint Corp. and Best Buy Co.