Percent Integrated Gradient Field Ratio for hardat.ru3 at radius 0.0175 m. 
  where Integrated Gradient Field Ratio = Sum[(abs(Bn/B2*sin(-n*theta_south_pole ))] for harmonics 3-16  

    Imag        Integrated Gradient Field Ratio 
    (A)                         %                 
  ---------     ----------------------------------  
  46.89528                    1.62854
  70.94595                    1.62266
  94.97795                    1.63328
 119.92242                    1.65119
 149.97976                    1.67220