Lubbock's nickname, "Hub City", derives from it being the economic, educational, and health-care hub of the multicounty region, north of the Permian Basin and south of the Texas Panhandle, commonly called the South Plains. The area is the largest contiguous cotton-growing region in the world and is heavily dependent on water from the Ogallala Aquifer for irrigation. CNNMoney.com selected Lubbock as the 12th-best place to start a small business. CNN mentioned the city's traditional business atmosphere: low rent for commercial space, central location, and cooperative city government. Lubbock is home to Texas Tech University, the sixth-largest college by enrollment in the state. Lubbock High School has been recognized for three consecutive years by "Newsweek" as one of the top high schools in the United States, based in part on its international baccalaureate program.