You could look at inflation adjusted per-capita sales, of course.

Ya, when I ask Gemini:

While there isn't a definitive inflation-adjusted per-capita number for 2025, recent data indicates that overall sales growth was outpaced by inflation, meaning consumers likely bought fewer items. Total Black Friday spending was up, but the average number of items purchased declined. For instance, Salesforce reported total spending was up 3% but order volume was down 2%, with average selling prices climbing 7%.

...

Per-capita sales: The increase in spending is largely driven by higher prices, meaning the actual volume of goods purchased per person likely decreased compared to the previous year, even with higher total spending, says The New York Times.