Could you please stop posting unsubstantive comments and flamebait? You've unfortunately been doing it repeatedly. It's not what this site is for, and destroys what it is for.
People reading in good faith understand what 99% means (it, as well as 95% etc., are commonly used that way, to mean "overwhelming majority"). Besides, if I wanted to write the actual number, which I happen to know, I'd have written 92,768%.
In any case, you don't have to justify the rudeness, a simple "sorry" would have sufficed.
“99%” when used like this is essentially an expression in English, for “almost all” or “almost certain.” It is very hard to believe that they have the actual statistic or that it happens to be exactly 99%, so I wouldn’t worry about anybody getting mixed up.
