The study, which was based on 2013 data from 1,847 Facebook Pages, examined the "reach" of content on those Pages among various age groups—i.e. the number of paid and organic interactions by those groups with Pages over time.
Interactions by 13-24-year-olds actually increased 29% in the 12-month period examined, the report found.
Moreover, interactions by the next oldest group, 18-24-year-olds, also increased in the same time period (up 39%). Overall, the 18-24 age group remains the most active demographic on Facebook.