As has been stated, this data is not that far off.
It is usually recieved by gathering ISP's when the site is visited.
So unless all you 16 year olds are paying for your own internet connection, this would be accurate.
I'm going to take a wild-guess. The majority of member's parents are 45-54 years old, and have a combined household income of over $100k a year.
Honestly, I'd say the data is spot on if you look at who buys your internet you are using the go on newschoolers.