Follow this link and it'll take you to Metrolink's report to GMPTE for service and performance...........whether you believe the report or not is another matter.
http://www.transportforgreatermanchestercommittee.gov.uk/downloads/file/4348/item_05_metrolink_service_performance
http://www.transportforgreatermanchestercommittee.gov.uk/downloads/file/4348/item_05_metrolink_service_performance