Total length – 18.5 kilometers (11.5 mi)[2] Number of stations – 31[2] Opened – 13 June 1992[2] Operating hours – 6.00 A.M. to Midnight[2] Frequency – 2 minutes (peak hour) to 15 minutes[2] Daily passengers – 320,000[2] Fare – TL 2.30, for students: 1.15 TL[8]