Well... I am 99% sure that you don't have to worry, but I am not that good at those percentage numbers...
One thing I can tell you is that you SHOULD NOT depend on that simulation... That's only a guide line... You should actually test your app/site in the situation where your users are going to use whenever you can...
For example, if you are creating a Flash website...
Set up the basic structure of the site, upload it to the server and test it...
Add a couple more sections to the site, upload it and test it...
Add the gallery section and upload/test it...
Add the contact section and upload/test it...
...
...
You get the idea...