Wish I could remember if it was Pensylvania or Delaware, but one of them had a helmet law then repealed it. Studies showed no decrease in deaths when factored for drivers and bike numbers over the years with a helmet law. They also noted periferal vision issues on some models of helmets (full faced). Two of the years they had an increase and attributed that to broken necks when the chin area of the helmet was hit.
It appears the first vital organ to stop working is the brain with head trauma so it was listed as cause of death but the statistical forms never asked the medical examiner if he would have lived with a helmet considering his neck was broken, both legs, flailed chest, internal injuries etc.
Many of the studies also claimed helmetless death on all deaths when in fact the guy was cut to ribbons by a truck and they had to pick up pieces. Everybody that dies without a helmet didn't die because they didn't have one. But everybody that didn't have one was included in helmetless death statistics.
I do think helmets save more lives than they take. I still say the stats don't matter. I say ride your own bike and respect the guy thats riding his.