I don't count the individual stones just the large ones and then estimate the volume of the remainder. It may looks like a lot but can often be no more than one or two tablespoons full, round about 15 to 30 mL. Yes I still have a spread sheet set up to estimate the cumulative volume and superimpose a best fit curve.
I general the stones are quite hard a plastic in nature, indicating that they are polymerised.
My health is still improving and over the last month, Psoriasis which I had on my knees and elbows has disappeared.