I had the crazy idea to keep track of a bunch of stuff I could think of...like average time per LD, number of LDs, number of times I've had a Layer x LD, average LDs per month, and so on. I arranged them into an excel sheet full of colorful graphs.
Like this one:
avg time per ld.jpg

If anyone has something similar, I'd be really interested in seeing what you've come up with.