Monthly data, not seasonally adjusted
National Railroad Passenger Corporation (Amtrak) trips of up to 250 miles are considered on-time if they arrive less than 10 minutes beyond the scheduled arrival time; 251-350 miles, 15 minutes; 351-450 miles, 20 minutes; 451-550 miles, 25 minutes; and greater than 550 miles, 30 minutes.
|Amtrak On-Time Performance||Apr-09||Apr-10|
|On-time performance (percent on-time)||84.1||81.2|
|Difference from same month previous year*||10.6||-2.9|
* Current month minus same month previous year. This is generally used in the case of bound numbers, such as proportions that cannot exceed 100%.
NOTE: The current value is compared to the value from the same period in the previous year to account for seasonality.
SOURCE: National Railroad Passenger Corporation (Amtrak), Monthly Performance Reports, available at http://www.amtrak.com/ as of June 2010.