Histogram of the mass flux at 1 AU in the solar wind based on hourly average measurements from ACE for the slow wind (black) and Ulysses for the fast wind (red). The values are represented in units of M_⊙ yr^-1 AU^-2 and have been multiplied by 4π so that they can be compared with the total mass loss rate of the solar wind. The vertical dashed lines show mass loss rates derived from the wind models of 1.6 × 10^-14 M_⊙ yr^-1 and 1.2 × 10^-14 M_⊙ yr^-1 for the slow and fast winds respectively. These are very similar to the medians for the two distributions shown in this figure.