In reply to Ian Bentley:
"is only completed by one per cent of climbers" implies that 1% of all climbers have completed it,
"only finished by one in every 99 climbers." implies that 99% of people that attempt it fail, both of which are different to the actual message,
"The route is graded 7c+, meaning around only 1 percent of climbers could manage it."
It's scary how the media just mangles stuff and you only notice when it is something that you know about.