[BorgHunter]

On-time performance has dropped dramatically in the past ten years. In the following article, look for the graph titled, "On-time performance by line, 2007 to 2017".

https://www.nytimes.com/interactive/2017/06/28/nyregion/subw...

[ricardoreis]

Thanks very much for the link.

But eyeballing that chart suggests an average deterioration significantly worse than 20 percent.