Under federal food labeling regulations, how much caffeine must be removed from coffee for it to be called decaffeinated?

High-quality decaffeinated coffees are becoming increasingly popular. According to federal requirements, every coffee labeled decaffeinated must have 97 percent of the caffeine removed. Despite the fact that coffee consumption in the United States has been continuously declining for the past 25 years, producers claim that those who do drink coffee prefer better quality, particularly high-grade decaffeinated coffees.