ab/2 rhoa a stdev 
2 81.42 1 1.05
3 71.77 1 1.05
4 57.13 1 1.05
5 49.13 1 1.05
6 40.44 1 1.05
7 36.18 1 1.05
8 33.92 1 1.05
9 33.00 1 1.05
10 33.17 1 1.05
11 33.63 1 1.05