Note: This is a sidebar to a feature story headlined 'Desert sprawl.'

People per square mile in metropolitan Tucson in 1953: 5,000

... in 1998: 2,400

Acres of Sonoran Desert land cleared for new homes, offices and commercial buildings each day: 12

Average annual temperature in Tucson in 1900: 67 degrees

... in the mid-1990s: 70.5 degrees (Pavement and buildings retain heat.)

Total annual vehicle miles traveled in the Tucson area in 1970: 2 million

... in 1997: 16 million

... expected in 2020: 28 million

Percentage of all Pima County vehicle trips lasting more than 30 minutes in 1968: 5

... in 1998: 15

Speed of rush-hour crosstown trips on major Tucson thoroughfares: between 18 and 30 mph

Expected increase in the staff of the Pima County Sheriff's Department by the year 2020: 874 people

Expected number of new jail beds in Pima County: 4,000

Number of rabbits, mice, rats, birds and reptiles eaten by a typical Tucson housecat each year: 80

Number of toads, rabbits, snakes, lizards, small birds, javelinas, coyotes and bobcats killed each year by automobiles in and around Saguaro National Park: 7,100

Sources: Pima County Administrator's Office, City of Tucson, Pima Association of Governments, Arizona Department of Economic Security, Pima County Sheriff's Department, University of Arizona School of Renewable Natural Resources, National Weather Service, National Park Service and U.S. Forest Service.