As per:
http://en.wikipedia.org/wiki/List_of_Christian_denominations_by_number_of_members
There are currently one billion non-Catholic Christians alive today. Add in all the non-Catholic Christians who have died, and you would have a figure of multiple billions. For the sake of argument, let's call it 5 billion. That would mean that for your 99% figure to be correct there would have to have been about 500 billion Catholics. This is rather problematic, given that there have only been (roughly) 100 billion people in all of human history (this figure assumes a starting point 50,000 years ago).
You caught me making the same (tongue-in-cheek) rhetorical argument made by the YEC's, but instead of agreeing that anyone who doesn't agree with them isn't Christian I posed that anyone who isn't Catholic isn't really Christian. Its just the same shoe on the other foot. I notice that that isn't a very comfortable fit for non-Catholics either and solicited an equal and opposite reaction from you and a few others.