The bar chart shows the percentage of small medium large companies which used social media for business purposes between 2012 to 2016

The figure depicts changes in how small, medium, and large businesses engaged in social media from 2012 to 2016.
 
Overall, three of business levels experienced a consistent increase of social media presence over five years, except in 2015. While large companies were the largest user, the small ones were the opposite.
 
Regarding two types of business, the small level used social media the least with 26% in  2012, followed by a marked rise to reach just below 50% in 2016, but drastically falling to 30% in 2015. It is apparent that about 30% of medium businesses used social media in 2012, and sharply fell to 30% in 2015, before growing to above 50% in 2016.
 
However, large businesses accounted for the majority of social media usage at 80% in 2012, and slightly decreased in 2013 and 2014 respectively, and suddenly dropped by approximately 30% in 2015. At last, there was a significant upsurge in 2016, reaching nearly the same as the starting figure.