[['airdate', 'celebrities', 'rating', 'share', '1849', 'viewers (millions)', 'weekly rank', 'prod code'], ['thursday , december 18 , 2008', 'william shatner , aisha tyler', '5.3', '9', '1.6 / 5', '8.27', '24', '109'], ['sunday , december 21 , 2008', 'julie chen , phil keoghan', '6.0', '10', '1.8 / 5', '9.52', '19', '112'], ['sunday , december 28 , 2008', 'adam carolla , betty white', '6.3', '10', '2.0 / 5', '9.84', '7', '111'], ['sunday , january 4 , 2009', 'craig ferguson , serena williams', '6.8', '10', '1.9 / 5', '10.43', '14', '108'], ['sunday , may 31 , 2009', 'jamie kennedy , norm macdonald', '4.5', '8', '1.2 / 4', '6.88', '20', '107'], ['sunday , june 14 , 2009', 'jeff garlin , chelsea handler', '4.4', '8', '1.0 / 3', '6.69', '22', '110']]
the episode on Sunday , January 4 , 2009 had the highest viewership of any episode
the episode on [ENT] had the highest viewership of any episode