Apple is the world’s most valuable company. Its yearly growth trend started in the early 2000s, with exciting new computers and a portable music player known as the iPod. The company continued to grow, with the introduction of the iPhone smartphone. Then, it introduced the iPad tablet. Sales of Apple products grew every year for 51 straight quarters. That all changed on Tuesday, when the company reported a drop in sales. Sales for the first quarter of 2016 dropped 13 percent. Sales dropped to $50.6 billion from $58 billion during the same quarter in 2015. The news caused Apple’s stock to drop, too. The company’s shares were down by about 8 percent in after-hours trading. Some experts say the struggling Chinese economy may be to blame for Apple’s weaker sales. The company’s report shows sales were down in China, Taiwan and Hong Kong by a combined 26 percent.