The city of Denver saw more tourists than ever in 2015 - one million more.

The numbers come from the Longwoods International annual visitor profile study. The organization has been studying Denver since 1994.

There were 16.4 million overnight visitors in 2015, a six percent increase from 2014.

They also spent nine percent more - a total of nearly $5 billion, which is a new spending record.

Leisure visitors totaled 13.8 million and business travelers reached 2.6 million. In the leisure category, 7.7 million people came to Denver to visit family or friends and 6.1 percent were "marketable" visitors, meaning people who could go anywhere but chose Denver.

Visitors spent more than $1.5 billion in Denver hotels and lodging and $1 billion on food and drinks.

Spending on gas, car rentals an other local transportation topped $1.46 billion.

Purchases at retail stores were $627 million, while $437 million was spent on Denver's paid attractions and other recreational and sightseeing activities.

When the numbers are averaged, business travelers spent $149 per day, marketable leisure visitors spent $136 per day and people visiting friends or family spent $71 per day.

An additional $12 million day visitors spent $671 million.

Other than Colorado, the most Denver visitors come from California, Texas, Florida, Illinois and Arizona.

The top cities outside of Colorado with the most Denver visitors are: Los Angeles, New York City, Chicago, Phoenix, Houston, Albuquerque and Dallas/Ft. Worth.

These were the top shopping and entertainment location for non-Colorado residents in 2015: 16th Street Mall, LoDo Historic District, Cherry Creek, Denver Pavilions, Park Meadows Retail Resort, Larimer Square, Outlets at Castle Rock, Belmar and FlatIron Crossing Mall.

The top paid attractions visited by non-Coloradoans were: Denver Zoo, Denver Art Museum, Red Rocks Park and Amphitheatre, Denver Botanic Gardens, Buffalo Bill Museum and Grave, Denver Museum of Nature and Science/IMAX, Downtown Aquarium, Colorado Railroad Museum, the Colorado Rockies, Butterfly Pavilion, Children's Museum of Denver and the Denver Broncos.

The top three free admission attractions were: Red Rocks Park and Amphitheatre, Coors Brewery and the Colorado State Capitol.