Find Rate: CRH Versus Actual Circulation

Something that I was musing about the other day:

Going through my coin collection (hoard), I noticed that some of my coins were sourced disproportionately from circulation (actual hand-to-hand cash exchanges) versus from hunting machine-rolled boxes.

A few observations:

Cents:
1909-1939- Most (about 10/15) were from circulation, especially old ladies with coin jars
1940-58- Didn't keep track, but most seemed to be from rolls
1959-1982- I seem to get about 30-40% in change, versus 20-25% from rolls

Nickels:
Buffalo- All (60+) were from rolls; have never gotten one from circulation (no surprise there)
War nickels- Mostly from rolls, but have gotten a few from circulation.
Pre-60 non-key- About even circ/roll ratio
Pre-60 key or semi-key- All were from rolls

Dimes:
Silver- Almost all (11/12) were from circulation, mostly from working as a cashier. The other was found in my wife's jar of tips from her old job.

Quarters:
Silver- All (3) were found in circulation. Two received as change, one from my old job.

I don't consider halves to circulate widely enough to really assess, but out of the ~15 that I received during my tenure as a cashier, 1 was 90% and 5 were 40%.

Has anyone kept track of change finds versus CRH finds? I'm curious to see other people's experiences with their change!