Railway, Mercedes-Benz USA, NAPA Auto Parts, Papa Johns, Porsche AG, Newell Brands, Marble Slab Creamery, and UPS. Over 75% of Fortune 1000 companies conduct business operations in the city's metro area, and the region hosts offices of over 1,250 multinational corporations. Many corporations are drawn to the city by its educated workforce; , 45% of adults aged 25 or older residing in the city have at least four-year college degrees, compared to the national average of 28%. Atlanta started as a railroad town, and logistics has been a major component of the city's economy to this day. Atlanta serves as an important rail junction and contains major classification yards for Norfolk Southern and CSX. Since its construction in the 1950s, Hartsfield–Jackson Atlanta International Airport (ATL) has served as a key engine of the city's economic growth. Delta Air Lines, the city's largest employer and the metro area's third-largest, operates the world's largest airline hub at Hartsfield-Jackson, and it has helped make it the world's busiest airport, in terms of both passenger traffic and aircraft operations. Partly due to the airport, Atlanta has been also a hub for diplomatic missions; , the city contains 26 consulates general, the seventh-highest concentration of diplomatic missions in the US. Broadcasting is also an important aspect of Atlanta's economy. In the 1980s, media mogul Ted Turner founded the Cable News Network (CNN), Turner Network Television (TNT), HLN (HLN), Turner Classic Movies (TMC), Cartoon Network (CN), TruTV (truTV) and the Turner Broadcasting System (TBS) in the city. Around the same time, Cox Enterprises, now the nation's third-largest cable television service and the publisher of over a dozen American newspapers, moved its headquarters to the city. Notable sports networks headquartered in Atlanta include, Warner Bros. Discovery Sports, NBA TV, Bally Sports South and Bally Sports Southeast. The Weather Channel is also based just outside of the city in suburban Cobb County. Information technology (IT) has become an increasingly important part of Atlanta's economic output, earning the city the nickname the "Silicon peach". , Atlanta contains the fourth-largest concentration of IT jobs in the US, numbering 85,000+. The city is also ranked as the sixth fastest-growing for IT jobs, with an employment growth of 4.8% in 2012 and a three-year growth near 9%, or 16,000 jobs. Companies are drawn to Atlanta's lower costs and educated workforce. Recently, Atlanta has been the center for film and television production, largely