I cannot seem to get my list down!

We both have quite large families.

I only have on the list including work/outside work friends 20 people invited for me but my list is still 108 people long

😫😫😫 I've went through and highlighted people who won't be coming because they live out of state but I still have to invite because they're family...that knocked it down to 92, so then I went back through and highlighted people who are family and live in state but that didn't show up to our siblings events, ok so now we're at 81. There are 4 kids, all my nieces so they will be there, but we can say 77. That's a little more manageable but what is the general percentage of people who DONT show up? I'm stressed out and wanting to get a good handle on a head count so I know how many center pieces to craft etc.