Each month the CRAs collect the amount that was on your statement and then, of that amount, how much you subsequently paid. These data stretch back at least 24 months.... e.g. Sept 2016, August, July, June, ... When a current or potential creditor pulls your report, he can see all 24 months of these amounts owed and subsequent payments. So he can see whether you always pay a particular card in full, or occasionally or perhaps often do not.
These kinds of data are called "trended data." For decades the CRAs did not collect them The only CC data they collected was the most recent reported balance. There was never a way to see of that balance how much you subsequently paid. And furthermore, every new month wiped out the record of the previous month. That's why FICO created models that were based solely on what your most recently reported balances were. Because there simply were no other data for FICO to use. That's also why consumers developed ways to game that system -- like paying all their cards to zero except one (even if that was very different from what they actually did most of the time).
Now however creditors can see a much richer picture of what you do. And recently Fannie Mae upgraded their Desktop Underwriter software to include a Transactor-Revolver analysis. Pretty much all mortgage lenders use DU so this is now part of how all loans are being evaluated moving forward. (Except, I believe, FHA and VA loans.)
Here's a recent discussion of trended data, the R-T distinction, and its future use by mortgage lenders:
http://ficoforums.myfico.com/t5/Credit-in-the-News/Equifax-going-to-report-balance-payment-amount-hi...
