I recently found an article on Mobile Vs. Desktop Usage worldwide. It confirmed my suspicion that in recent years mobile usage has surpassed desktop usage overall.
Think about how many people spend their working day on a computer. Then compare that to time spent on the phone. According to the article, the U.S. population spends 50% of their time online on their desktop / laptop, 46% on their phone, and 4% on tablets. This trend toward mobile will surely only increase.