Nearly two-thirds of American adults now use social networking sites, up from 7% in 2005.
This and other interesting data can be found in the latest Pew Research report.
Among other things we find that:
Usage among those 65 and older has grown so that today 35% of those over 65 use social media. This was just 2% in 2005.
68% of all women use social media, compared with 62% of all men. This confirms recent trends bringing men up to par with women who used to be more likely to use social media.
Higher-income households are more likely to use social media but today 56% of those living in the lowest-income households also regularly use social media.
Those who live in rural areas are less likely to use social than those in suburban and urban communities – 58% of rural residents, 68% of suburban residents, and 64% of urban residents use social media.
For full details see the results here http://www.pewinternet.org/2015/10/08/social-networking-usage-2005-2015/