It's in the reports that we'll deliver to the committee. But there are three revenue streams that an issuer receives when it runs a credit card portfolio: interest, fees, and interchange. When one of those goes down, you have to adjust the others to operate within the margin requirements of prudent banking.
This is well documented. It did happen in Australia, and you can look in Canada to credit card systems that don't have interchange, such as retail store cards, which have interest rates approaching 30%, versus the 65 low-interest-rate programs available under the system involving interchange.