What is the 0.01% of germs?

Understanding the 0.01% of Germs

This statement does not assert the ability to eliminate 99.99% of all bacteria and viruses; instead, it indicates that only 0.01% of a given population of germs will remain. For instance, if there are 1 million bacteria present on a surface (which isn't an excessively large amount in certain cases), a disinfectant that eradicates 99.99% of them would leave 100 surviving bacteria. So, what exactly constitutes the 0.01% of germs that withstand such cleaning methods?