What percentage or how much of the clothes were never worn?

With the twins we prefer one pieces (PJs/sleepers) and sometimes put them in onesies and pants. We didn't dress them up that often in dress clothes (dresses and dress shirts & pants) so they weren't worn either. Pictures with Santa was the last time they were dressed up.

Also, I had a lot of short sleeve onesies that were not used because they were were born in the fall and it was too cold to wear. We did want to get use out of them so we got long sleeved shirts to put under them. But putting an extra item on was definitely not high on my list so I preferred putting them in long sleeved onesies. DH is always hot and putting them in s/s onesies and I always have to put socks or put a cardigan on top.

I know one tip is to not wash anything until it needs to be used but I like to pre-wash everything I buy.

So do you usually have a lot, some, very little that were unused?

ETA: Oh, I did recently learn that 3 months means 0-3m so I didn't get much use out of that size because I started them too late. Looking into the future, some of the clothes I got at consignment are probably the wrong season because of this sizing issue.