In our final Number Crunch for the year, we thought it fitting to look back on the state of social media over the past 12 months.

It's been another bumper year for Facebook and Facebook, while Twitter navigated stormier seas.

Elsewhere video became the hottest form of content, yet Google Glass didn't look like getting a release anytime soon.

Facebook world

There are now over 2.08 billion users with a social media account. More than half of these are on Facebook, which ends the year with 1.4 billion users.

But the bragging rights don't end there. Facebook also owns Instagram (400 million users) and the world's most popular messaging platform WhatsApp, with 900 million users.

And let's not forget Facebook also owns Messenger, which currently clocks up over 700 million users.

Mobile

In 2015 social media users were on the move, more than ever.

There are now 7.1 billion mobile connections around the globe, which outnumbers the amount of people on the planet.

2.7 billion of these are smartphone connections, and there are 1.65 billion mobile social accounts.

Over 83% of Facebook's users now access the network from a mobile device.

Video

Social video became a bonafide blockbuster in 2015.

The number of videos viewed on Facebook doubled from 4 billion to 8 billion in less than six months, while Instagram rolled out support for video ads.

YouTube continued to experiment with new subscription models. One of these, YouTube Red, lets users pay a subscription fee for an ad-free service.

Today, over 50% of mobile traffic is now made up of video content.