@Front Ranger You don’t have to run the calculations yourself. Just plug in the data into an online calculator like this:
https://www.socscistatistics.com/tests/spearman/default2.aspx
Doing some poking around for snow in EUG in Jan 1937. I found that Cottage Grove had 9.8, but still had some missing days. Found another close one that had 5.6 with one missing day. Lousy record keeping there back then.
My dad has over 40 ash trees on his property and the borer is confirmed in the lower Pudding drainage. It’s a lowland species here. We don’t have any on our property.