You don't visit enough my friend :)
It's down about 8.4 minutes per week. On 26% of days it doesn't work at least once, and on 12% of days it has more than one consecutive failed check. The longest uptime streak was 24 days
I've been keeping track since exactly 2 years (to the day!) because I was surprised that it seemed briefly down for me on a daily basis. Was I getting unlucky and hitting it every time, or was it just down very often? Nobody posted anything so I started answering the question for myself :p
I've been meaning to post the tracker to HN but there's a pesky bug I want to fix: the "is it currently down" stat. I don't know how this is beyond me but something in the code bugs out. So this is my first time posting about it
Would love to see it when you do get round to posting it :)