That’s actually a tough question. Sandy came out as 75.83% on the age-grade tables from HyTek Meet Manager, which is what Leone Timing uses, and Edna was 56.17. I was confused by this too, and actually called Pat Leone in the middle of the Cornell meet to confirm that it was right.
You can read more about it here, but the other thing to keep in mind is that HyTek hasn’t necessarily updated its tables to match the latest data from World Masters Athletics.
Howard Grubb is one of the key people involved.
https://www.howardgrubb.co.uk/athletics/
Regardless, we awarded Sandy and Edna the equivalent prizes that they would have gotten for 100% age grading. Only seemed fair.