I've always thought it was unfair that the 9 in 9% uptime doesn't count.
"1 nine" tends to mean "90% availability" i.e. 37 days of downtime per year.
9% availability would be an uptime of ~33 days a year, I think at that point, we're pushing the semantics of "available" if the service is down the entire year except one month on average.
I offer a nine fives colo.