One-way ticket prices dropped from an average of $218 to $176 during that time.
The drop in price mirrors the growth of discount airline seats at DIA.
The airport still has higher average domestic fares than many of the nation's top markets.
In a separate survey of airline passengers, DIA was ranked second among global airports just behind Frankfurt Germany.
The 2002 survey by JD Power and Associates relied on email responses from about 12,000 residents in 16 countries.