Nickelodeon’s new live-action comedy series, “Zoey 101,” starring Jamie Lynn Spears, was the network’s highest-rated premiere among tweens in almost eight years. Its debut on Sunday at 8 p.m. averaged a 7.9 rating in the 9 to 14 demo, representing 1.6 million viewers, up 55 percent from the time period a year ago. Another episode of “Zoey 101” drew a 8.1/1.6 million tweens at 8:30 p.m. The show attracted more than 3 million viewers of all ages. The last Nickelodeon show to open so well was “Allen Strange,” which got an 8.1 rating in its Nov. 1997 premiere.