Have you noticed that the average length of the papacy is growing pretty rapidly at this point in history? Two hundred years ago the average reign was 2, maybe 3 years, and many only held the seat for a few days or months before dying, abdicating, or running for their lives. But by the middle of the thirteenth century, we've reached a fairly stable time. Gregory's rule was fairly short compared to his time - about 14 years from 1227 to 1241.