Season Episodes Time slot (EST) Original airing Rank Viewers
(in millions)
Season premiere Season finale TV season
1 23 Friday 9pm/8c (October 6, 2000 – January 12, 2001)
Thursday 9pm/8c (February 1, 2001 – May 17, 2001)
October 6, 2000 (2000-10-06) May 17, 2001 (2001-05-17) 2000–2001 #10 17.80[11]
2 23 Thursday 9pm/8c September 27, 2001 (2001-09-27) May 16, 2002 (2002-05-16) 2001–2002 #2 23.69[12]
3 23 September 26, 2002 (2002-09-26) May 15, 2003 2002–2003 #1 26.20[13]
4 23 September 25, 2003 (2003-09-25) May 20, 2004 2003–2004 #2 25.27[14]
5 25 September 23, 2004 (2004-09-23) May 19, 2005 2004–2005 #2 26.26[15]
6 24 September 22, 2005 (2005-09-22) May 18, 2006 2005–2006 #3 24.86[16]
7 24 September 21, 2006 (2006-09-21) May 17, 2007 2006–2007 #4 20.34[17]
8 17 September 27, 2007 (2007-09-27) May 15, 2008 2007–2008 #9 16.62[18]
9 24 October 9, 2008 (2008-10-09) May 14, 2009 2008–2009 #4 18.52[19]
10 23 September 24, 2009 (2009-09-24) May 20, 2010 2009–2010 #12 14.92[20]
11 22 September 23, 2010 (2010-09-23) May 12, 2011 2010–2011 #12 13.52[21]
12 22 Wednesday 10pm/9c September 21, 2011 May 9, 2012 2011–2012 #21 12.49[22]
13 22 September 26, 2012 May 15, 2013 2012–2013 #25 11.63[23]