I actually wonder if it really is a normal distribution. A lot of people think any distribution with spread is a "bell curve". In a lot of fields like this the

I actually wonder if it really is a normal distribution. A lot of people think any distribution with spread is a "bell curve". In a lot of fields like this the tails are a lot fatter than they should be in a normal distribution. And doctors (author is a surgeon) don't get much statistical training. I was once told by a doctor that all random distributions are normal curves.