I found some statistics, but they don't include debit (or credit) cards, just normal transfers between banks: http://www.paymentscouncil.org.uk/resources_and_publications... .
Looking at "1990 to date", I'm not sure I'm reading the tables correctly. Were there really 265 million cheques processed in January 1990? That's 10 for every household. Last month was 46 million, 1.7 for every household — still seems high.
In any case, it compares with over 620M electronic payments for December 2014.
I probably write 2-3 physical checks a month (housekeeper, random other service people, personal payments for various activities) and another 2 to 3 from my bank. And that's with doing all the automatic payments for utilities etc. that I can.
The numbers show 13× as many electronic payments as cheques, and I can believe 10 electronic payments per person (salary, six or seven bills, couple of credit cards, plus business use).
That's atypical in my experience in the US. The dealer has always wanted me to get a certified (may not be the technically correct term) from my bank. Not that it's a big deal; you go to the bank, they put a hold on the amount in your account, and they stamp the check a couple times.
That said, checks still tend to be favored (even if they're issued directly from the bank) for many recurring payments, local service people, individual to individual casual transactions and the like.