Though it may not mean the end of the world’s most popular social network, the demographic shift in Facebook members is leaving some analysts worried. Already reports are showing that Facebook is dead to teens, who are switching to more private platforms such as Twitter and messaging apps. Now new data is showing that, yes, Facebook has failed to keep up its teen member numbers over the past few years.

Market research firm iStrategyLabs this week released a new report on Facebook demographic that shows the social network has lost over 11 million addressable high school and college-age members over the past three years. High school Facebook membership has dropped a whopping 58.9% since 2011, while college Facebook membership has dropped a similar 59.1%. While the huge growth of college alumni (up nearly 65%) in the past three years shows that many of the first Facebookers are sticking with the service, the loss of so many college students shows that even some high schoolers who began their social media experiences on Facebook are moving on to newer platforms.

As seen in the chart above, the age groups most quickly abandoning Facebook seem to be the youngest. The number of children aged 13 to 17 on Facebook dropped over 25% during the past three years while the highest growth was seen in the 55 and over age group. Facebook now boasts around 56 million addressable members between the ages of 35 and 54.

With these sorts of numbers it isn’t hard to see why teens might seek out a place online where their parents (and grandparents) might become a part of their immediate social world. In addition, the proliferation of smartphones in the past half-decade seems to have given more private platforms such as Twitter and Snapchat extra value to younger social media users.

Image via iStrategyLabs