Q:

Ngrok connections line meaning

I have just set up ngrok, and read through the parts of the documentation pertaining to ssh, which is what I am using it for.
On the "host" or "server" device (not sure of the correct name), it shows a text UI, with a line for "Connections", with multiple columns. The columns are labelled "ttl" "opn" "rt1" "rt5" "p50" and "p90". There are numbers under each, which change occasionally.
I wish to know what each of the columns mean, as I have made many searches for "ngrok" and the labels, but nothing conclusive has come up in terms of their meanings.
Can anyone tell me what each of the labels mean?
(copied from stack overflow at a commenters request, please tell me if I'm in the wrong spot)
Update: When pulling the info from the API, some of the labels have longer names: "metrics":{"conns":{"count":79,"gauge":0,"rate1":2.457246109955258e-7,"rate5":0.00038372479383272124,"rate15":0.0008963016058921416,"p50":213239525,"p90":312309088089,"p95":596862711946,"p99":925411600728
With the longer names, some become more clear, like count and rate. But I'm still confused on what the numbers mean. Perhaps percentiles? 
If anyone has any info that would be greatly appreciated.

A:

I have never been able to find documentation for these status's myself however if you browse to http://localhost:4040 on the machine where you have established the tunnel you will access the Ngrok client API where these status's are displayed in a real-time web UI.
They are essentially statistics on the Connections, Connections Duration, HTTP Requests and HTTP Request Durations.  

