99.9999% is harder since groups of say 10K are going
to have more of an impact.
If my maths is right, 99.9999% of the world's populations leaves about
6,500 people that we can not cater to - a group of 10K that only speak
one language would require us to cater for their language.
If Greg actually meant 99.999%, which his later email would
suggestion, then it's 65,000, which is slightly more doable.