A bullet fired outside the Georgia Dome on New Year's Eve tore through the stadium's roof and struck a teen-ager in the leg. The 18-year-old University of Georgia freshman was sitting four rows up from the field at the Peach Bowl football game when she felt a burning sensation in her right leg. An X-ray revealed a nine-millimeter bullet just below the knee. Police think the shot was fired into the air by someone celebrating the new year. Three years ago, a stray bullet grazed another spectator at the same bowl game in the same domed stadium.