Probability distribution, , of the location angle (λ) as derived from the magnetic data of MCs observed at 1 AU and fitted by the Lundquist model (Lepping et al. 1990). The data are grouped into a histogram having 10 bins of |λ| and is normalized so that the sum of the bins is unity. A least square fit of the histogram with a straight line and a cosinus function are shown in black and blue, respectively.