Impact of Parent Longevity or COI on Lifespan

Results: in comparing 2 groups of Goldens (i.e., one with shorter life spans and one with longer lifespans)
the longer lived Goldens had,
on average, longer lived parents and lower COI.

Longevity is, doubtless, a complex mix of many competing factors. It would be easy, otherwise, to produce long lived
Goldens. It is commonly supposed that two factors that actually influence longevity are 1) possessing a low COI and 2)
having long lived parents. It is well known that these are not hard and fast indicators of longevity. For example, In one
litter with a COI of 56.9% there were 2  who lived to 13 years (well past the average lifespan) and 1 who died at 2 years.
The following plots offspring life span versus parent lifespan (6792 data points) . Clearly there is a lot of scatter.
Now COI versus Lifespan (5036 Data points).