Customers payment method usage statistics

Hi All, UK based. 16-25 demgraphic. I have a client looking into their payment gateway/merchant accounts. They have noticed there is a split in charging between credit and debit cards and have asked if I have any stats on what type of card a customer uses.

I have found some info online that gives EU stats for 2008 as follows;

Credit Card - 41%
Debit Card - 36%
PayPal - 33%

Does anyone have any further info on this specifically for a UK market and second question, is this something they should be asking me to do the work on (i quoted for building the shop and integration based on a design, that’s it, not making decisions for them related to their desired business outcomes) or is it something they really should have researched themselves when deciding that they need to sell online?