Economists at the University of Chicago recently published a paper (PDF) with the National Bureau of Economic Research that examined the best indicators of wealth over the last few decades. And it found that in 2016, the last year it analyzed, there was a 69.1% chance of accurately guessing that a person was wealthy if he or she owned an iPhone.

Apple’s iPad was a predictor in 66.9% of cases. It was followed by being a Verizon Wireless customer at 61% and owning an Android handset at 59.5%.

Using Kikkoman soy sauce was the fifth-most-likely indicator at 59%.

Aside from products, the economists, whose findings were earlier reported on by Business Insider, found that if traveling in the U.S., owning a passport, and having Bluetooth in your car were also high on the list of high-income indicators. Having a heated seat in your car or using dishwasher detergent were also good wealth indicators.

The findings show a distinct difference in wealth indicators over the years. For instance, in 1992, there was a 62.2% chance that if you were using Grey Poupon dijon mustard, you had some cash. In 2004, that was true if you wee a Land O’ Lakes Regular user. That same year, if you bought a new vehicle, there was a 73.6% chance you were wealthy.

One other tech-related takeaway from the study: Owning a Sylvania TV in 1992 meant there was a 57.4% chance of accurately identifying you as wealthy.