What are you doing to effect the absolute separation of church and state?
I hadn't considered the full impact of the numbers of percentage of people that state non-religious views too much before know, but looking at the data collated in this Flash graphic - and thanks to the fragmentary nature of Christianity - this non-religious group accounts for a good proportion of the population even in the most pious states.
Indeed, as a bloc, the non-religious constitute similar figures to Catholics and are often the second largest group in total.