Piper Jaffray has released the results of its 16th bi-annual Teen Survey, which asks a sampling of high school students about their interest and buying patterns in the realms of MP3 players, online music stores, and music-playing cellphones. When asked about the iPhone 8 percent of the 769 participants said they already owned one, with another 22 percent saying they planned on purchasing an iPhone in the next 6 months. Those responses are up from…