Jaimie,
These are interesting figures and it involves an area of the industry where opportunities exist to reduce the costly loss of mares not producing live foals.
For the last couple of years Pepper Tree Farm have been carrying out regular ultrasound scans of the pregnant mares placentas in an effort to reduce the percentage of mares who abort their foals. The scan enables early detection of infection which, with appropriate treatment with antibiotics, can result in a live foal where an abortion or early foal death could otherwise have occurred. I am not sure if they have statistics that measure the effectiveness of the practice.