For instance (LIRR mention here)

Percent of on-time* trains during AM peak

After a rocky January, Long Island Rail Road performance data for 2018 was close to, and often better than, 2017 levels. After June, the story changed and 2018 percentages fell below those from 2017. Click below any month to rewind the data points, or hit replay to see it all again.

* The LIRR considers a train on time if it arrives at its final destination within 5 minutes and 59 seconds of scheduled arrival time.

Then we have a table of the times for all branches.