This assumes cash transactions are actually recorded. Given the increasingly invasive surveillance of digital transactions, I expect the numbers and reality to diverge more as time progresses.

Also, to be pendantic about it, I've never actually seen someone spend hard cash, just fiat currency, which has much lower value.

I do keep a US Minted dollar handy, should the need arise for hard currency. Made in 1901 at the New Orleans mint

edit/clarify: Yes, a 1901 Morgan Silver Dollar, a coin with a current melt value of $39.64 according to coinflation