We're also seeing a steady rise in balances and what may be the beginning of a spike in difficulties paying on that debt. Understandably, the most dramatic jump in charge-offs in credit card debt was in the depth of the recession, hitting a high of 4.57% in the first quarter of 2010. This came right after the height of credit card delinquencies seen one quarter prior, at 2.02% in the fourth quarter of 2009.

Both those measures fell as the economy improved, but then charge-offs jumped sharply in the past six months to 2.57% in the first quarter of this year. Delinquencies, meanwhile, rose slightly but then headed back down.

Perhaps this is the result of credit unions getting bad debt off their books or perhaps it's a sign of something more. Only time will tell. But what we can see is that credit card use is growing along with everything else in the movement, including membership, mortgages, overall lending, shares and even the workforce.

We documented all that in our First Quarter Trendwatch — check it out at CreditUnions.com — but it's interesting to note again how credit card penetration is moving up in lockstep with some other measures of member engagement.

A critical indicator there is the percentage of credit union members who have a checking account. Share draft penetration has moved well past the halfway point in the past 10 years, from 44.7% to 56.5%. Auto loan and credit card penetration also moved up, although not quite as much, and real estate penetration actually is down slightly, although first mortgage share of the overall market is at an all-time high.

What's not at an all-time high but still pretty substantial is how much of their credit card credit line that credit union members are using. We see that by charting unfunded commitments and utilization rates. The accompanying graph on page 10 includes both what percentage of their available credit all those millions of members are using, and how much that available credit itself has grown.

Ten years ago, just before the recession, that was 27.7% usage of $71.5 billion in available credit. Ten years later, it's 31% of $116.1 billion in available credit. The utilization rate has been a bit higher in the immediate past, reaching 32.2% in 2013, but it began a gradual descent as the amount of available credit — including those unfunded commitments — rose sharply as the recovery took hold and consumers were offered bigger chances to go deeper in debt.The result? We can see that even as unfunded commitments have gone up, utilization has stayed about the same. That means higher average balances, which indeed have risen from $2,138 in the first quarter of 2007 to $2,770 in the first quarter of 2017. That's higher than the rate of inflation.

Could all this have something to do with the sudden rise in net charge-offs and smaller but still notable increase in delinquencies? Is the economy the macro reason? What's going on here? Only time will tell.

As for the stegosaurus? He lets the shopping do the talking.

Liz Furman is Senior Industry Analyst at Callahan & Associates. She can contacted at 202-223-3920 or [email protected].