Here is some old O&D data but I'm sure its very consistent you,
2009 Data
Metro          Daily O&D      total     total O&D    O&D %  # of Airports
New York	 127,801   51,883,694   23,131,981  44.60%  6 airports
LA Area		 119,346   38,092,034	21,601,626  56.70%  6 airports <-----
DC Area		 91,733	   29,917,661	16,603,673  55.50%  3 airports <-----
SF Area		 87,419	   26,179,300	15,822,839  60.44%  3 airports <-----
Chicago	         86,821    39,281,585   15,714,601  40.00%  2 airports
Miami	         79,636    31,262,044   14,414,116  46.10%  3 airports
Las Vegas        73,138    20,224,090   13,237,978  65.50%	
Orlando          68,040    18,211,975   12,315,240  67.60%  2 airports
Dallas/Ft.Worth  59,577    31,149,065   10,783,437  34.60%  2 airports
Atlanta	         56,645    43,008,154	10,252,745  23.80%	
Phoenix	         54,040    18,968,897	 9,781,240  51.60%	
Denver	         53,747    24,337,554	 9,728,207  40.00%	
Boston	         44,673    12,068,312    8,085,813  67.00%	
Seattle	         43,376    14,787,443	 7,851,056  53.10%	
Philadelphia     41,860    14,878,298    7,576,660  50.90%	
Houston	         39,021    23,606,848    7,062,801  29.90%  2 airports
Tampa	         38,865     8,888,162	 7,034,565  79.20%	
San Diego        36,242     8,171,820	 6,559,802  80.30%	
Minneapolis      34,399    16,173,119	 6,226,219  38.50%	
Detroit	         33,128    15,715,346    5,996,168  38.20%	
Salt Lake City   22,696     9,988,837	 4,107,976  41.10%	
St. Louis        22,361     6,258,829	 4,047,341  64.70%	
Portland         22,144     6,116,995	 4,008,064  65.50%	
Sacramento       20,175     4,356,274    3,651,675  83.80%	
Kansas City      19,973     4,685,648	 3,615,113  77.20%	
Charlotte        19,562    17,215,648	 3,540,722  20.60%