Histogram of hourly average solar wind speeds measured by the spacecraft ACE (green) and Ulysses (blue). The vertical dashed black and red lines show typical slow and fast wind velocities respectively. We have only considered Ulysses measurements from when the spacecraft was less than 2.5 AU from the Sun. The distributions from the two spacecraft are different because they probed the solar wind at different latitudes. The orbit of ACE is in the equatorial plane, and therefore ACE measured mostly the slow component of the solar wind. The orbit of Ulysses is almost perpendicular to the equatorial plane, and therefore Ulysses measured both the slow and fast components of the solar wind.