Graph showing average daily use of D.C. Metro

The graph shows that the average daily use of D.C. Metro on different time. From 6:00 am, the number began to rise, and reached the 1st peek at around 8:00. After that, the number declined considerably. After slightly growing from 10:30, the number stabilized for a period. Subsequently, the number dipped sharply with reaching a bottom. At 18:30, the number reached 2nd highest level. The number, from then on, dropped steeply, and eventually remained relatively steady after 20:30. The graph shows that the number of people using metro changed dramatically during two periods because mass people were traveling to or from working in rush hours.