According to a report on The Verge, the PC shipments have been on a steady decline in the last 5 years in a row. The Verge cites Gartner and IDC as seeing only approximately 270 million machines shipped in 2016. Both Gartner and IDC have differing opinions on the reason for the decline or what will happen to the future of the PC industry.
Gartner believes the PC enthusiasts market is "not big enough to drive overall market growth.” On the other hand, IDC had a different outlook:
"The fourth quarter results reinforce our expectations for market stabilization, and even some recovery. We have a good opportunity for traditional PC growth in commercial markets, while the consumer segment should also improve as it feels less pressure from slowing phone and tablet markets."
In 2011, 365 million PCs were shipped worldwide. It's unlikely the PC market will return to those 2011 numbers anytime soon, if at all.