much appreciated
I will edit this as I go.
Firstly, this report is from 1990, that is 25 years ago, I'm not sure how relevant its statistics are, however I will look for citations of this article in further papers (Beyond the 1994 paper I myself links) to see what the community currently understands about these statistics.
I will reply to this in the next few days once I have time to properly access and read the peer reviewed studies