Serious and sexy question!!

So I have a serious question for everybody out there. What are the thoughts on i****t between consenting people? How many people have thought about a family member in a sexual way? Let me just say that even though I love fantasizing about it I'm not asking because I get turned on but because I am honestly curious about how common it is. I thought the best place to ask would be a site like this. I have looked online for real data but it is very hard to find. Basically I'm trying to figure out if wanting to fuck your family is something lots of people at some point think about but never talk about for obvious reasons or if it is very rare and the views of many not just that of a small influential group.