[xvedejas]

If 90% is one nine and 99% is two nines, we can use the logarithm to compute how many fractional nines we have at 98.59%: about 1.9788 nines (almost two!)

[bhelkey]

I think it was a joke that 98.59% has 2 '9's: 9X.X9%.

[xvedejas]

Yes, you're correct about that