Apple this week posted its first-ever year-over-year decline in iPhone sales, and first revenue drop in 13 years.

According to Tuesday's results, Apple sold 51.2 million smartphones in the most recent quarter, down from 74.7 million in the previous quarter and a 16 percent drop from the same time last year when it sold 61 million iPhones. Cupertino also sold 10.2 million iPads, down from 16.1 million in Q1, and 4 million Macs.

"Our team executed extremely well in the face of strong macroeconomic headwinds," CEO Tim Cook said in a statement. "We are very happy with the continued strong growth in revenue from Services, thanks to the incredible strength of the Apple ecosystem and our growing base of over one billion active devices."

That includes a milestone 13 million Apple Music subscribers—up from about 10 million in January.

Cupertino ended the second quarter with $50.5 billion in revenue—a 13 percent drop over last year, and one-third of the revenue earned last quarter. As the New York Times notes, the dip can be attributed to weakness in markets like China and the lack of an innovative new product to hold people's attention. This year, Apple has only unveiled updated versions of existing products, the iPhone SE and 9.7-inch iPad Pro.

Apple isn't the only tech firm that saw declines: Microsoft, Google, and Twitter also reported lower-than-expected financial results, according to Reuters.