Sure...I had already referenced the citation in two other posts today in different threads so I didn't do it here, but I found this when we were researching the risk of breeding the female yorkie, but I was able to post it in that a thread as the thread was closed before I could do so.
The survey is cited and some of the results are presented in "table" or graph form on page 148 of this veterinary article on dydtocia.
http://www.intl.elsevierhealth.com/e-books/pdf/974.pdf