Cumulative Production By Formation -- The Williston Basin, North Dakota, USA

Source: NDIC website. Some numbers rounded. Last two data points in each row were calculated from the NDIC numbers. Numbers subject to error. Typographic errors possible. For personal use only but others are certainly free to do what they want with these numbers. 

Through 2011
Madison (46%): 923 million bbls; 5,523 wells; 167,144 bbls/well; 0.6% over previous year
Red River (10%): 2 million bbls; 1,252 wells; 191,764 bbls/well; 3.5%
Bakken (16%): 3 million bbls; 3,578 wells; 92,480 bbls/well; 5.6%

Through 2010
Madison (49%): 915 million bbls; 5,505 wells; 166,176 bbls/well; 0.3%
Red River (14%): 2 million bbls; 1,238 wells; 185,323 bbls/well; 3.9%
Bakken (11%): 2 million bbls);  2,308 wells; 87,542 bbls/well; 14.6%

Through 2009
Madison (52%): 901 million bbls; 5,469 wells; 165,546 bbls/well;
Red River (13%): 2 million bbls; 1,220 wells; 178,321 bbls/well;
Bakken (7%): 1 million bbls; 1,566 wells; 76,385 bbls/well;