There's a broad hint of an overall negative slope. But if you lop off a few points on the right and the left, the remaining central cluster is relatively shapeless. But, there does seem to be some negative slope to at least certain line segments, so that might mean something.
My first cut at figuring this out was to download the FRED data and make a new plot - Graph 2 - with line segments separated in what I hope is a coherent fashion. I did this by eyeball, then labeled the segments according to the dates they include. In the process I inadvertently reversed the axes, but this shouldn't change whatever conclusions might be drawn.
There are 10 line segments. This is still a plate of spaghetti, but some order can be discerned. There are some downward sloping segments, but also some straight verticals. For clarification, I broke this into two different graphs, of five segments each. Graph 3 has the first 5 segments spanning Q1 '80 to Q2 '91.