It is a graph of the average number of barrels of well produced per well in North Dakota for each year since 1951 when there was one well. There is one exception: the last two data points are January, 2010, and June, 2010.
So, "1" on the horizontal axis = 1951 and "56" = 2007. The last data points are 2010.
During earnings season, many of the oil companies operating in North Dakota update their presentations. As usual, we see the huge decline rate in Bakken wells. A typical Bakken graph will show an initial production of 1,000 barrels of oil in 24 hours, but it will decline rapidly and stabilize at 200 barrels of oil.
On January 1, there were 4,391 wells, and average daily amount of oil produced in January, 2010, was 236,175 barrels of oil. In June, 2010, there were 4,751 wells, and the average daily amount of oil produced in June was 314,602 barrels of oil.
The graph speaks for itself.
I was curious how the 200 bopd stacked up against historical averages, so I put the NDIC data into a graph.