This is meaningless. If the majority of that 15% comes from big planed purchases, but 99% of the stores that sell food do not take cards, you will eventually se

This is meaningless. If the majority of that 15% comes from big planed purchases, but 99% of the stores that sell food do not take cards, you will eventually see bread riots on the street as the implementations of the cashless economy proceeds. The actual question to ask is, for how long could an average citized go without cash without failing to acquire an esential supply at regular market value? And how does the figure change if you are willing/able to pay at any price point?