July 2009 was the busiest month in the history of Denver International Airport, airport officials announced Wednesday.There were 5,109,342 passengers at the airport, exceeding the previous monthly record by 2.2 percent.The previous record was set exactly one year earlier in July 2008, with a little over 5 million passengers, DIA said.Even though the summer month was good, overall, DIA has seen a drop in passenger traffic and flight operations for 2009. The record for all-time passenger traffic in a year was set in 2008, with 51.2 million passengers.A DIA aviation manager said they were encouraged to see the increase in flight travel. Airport officials consider the Denver market very strong in air travel, and even though they expect to finish the year with low numbers, they are looking forward to that changing.This is certainly good news for Denver International Airport, Aviation Manager Kim Day said Tuesday. "We've been seeing our numbers drop since last October and it is refreshing to see them headed in a different direction. Although we still anticipate finishing 2009 down overall, I think that this is an encouraging sign and certainly a reflection on how strong the Denver air travel market really is."