https://wiki.debian.org/ReproducibleBuilds has some more infos; some is outdated, but it also has a chart showing how many packages are built in the CI, and how many of those are reproducible builds.
(Orange = FTBR = "failed to build reproducibly")
I'm not good at reading numbers from charts, but I'd guess it's a few percent (4-5ish?).
all I get is this:
> Forbidden
> <p>You are not allowed to access this!</p>
(yes, with HTML tags on display) :)
EDIT: I also found a "I Challenge Thee" page in history. did I just get blocked by antibot measures? why???