The Metropolitan Transportation Authority (MTA) operates most of New York City's transit systems. Using census data, the MTA reported in August 2006 that ridership on its buses, subways and commuter trains in recent years has grown faster than population growth, indicating that more New Yorkers are choosing to use mass transit, despite the poor service in some areas of New York City by mass transit.[21] The MTA attributed the ridership gains to the introduction of the MetroCard in 1993, and the replacement of more than 2,800 rolling stock since 2000.