The Great Dakota Divergence
Both numbers are before inflation adjustment and compares with a national average of a 3.5% increase (also unadjusted for inflation).
The secret behind North Dakota's spectacular boom can of course be summarized in three letters as "O-I-L". I am however not so sure why South Dakota did so badly this year. but it might just be something temporary as it had above average (though still well below the North) growth last year.