For years, Facebook has been one of the most popular social media sites in the world. But the site is struggling amongst a certain demographic, according to a recent survey.

According to a recent study by Frank N. Magid Associates Inc., Facebook is now being used by 88% of 13-17 year old social media users in the United States. That is a six percent drop from last year’s number. Other social media sites and apps such as Twitter, Instagram and Snapchat are growing in popularity within the same age group, according to the study.

While there are a plethora of possible reasons for the slippage in popularity amongst the 13-17 year old age group, one of the main reasons that it is believed that other social media sites are gaining popularity while Facebook is losing popularity is because of the age of the users on each respective site. Over the past few years, older adults (parents and grandparents) have gradually started to use Facebook more. The harsh reality for Facebook is that no teenager once to be friends with their parents on a social media site. Sites like Twitter and Instagram, for the most part, are less likely to have parents and grandparents on them, making those sites “cooler” because of an overall younger audience.

There are over a billion people on Facebook, but it is unknown exactly how many people actively use Facebook. Most studies agree that the number is somewhere between the high hundred millions and the low billions. So with or without 13-17 year olds, Facebook is still one of the most actively used sites in the world.