Helios hourly data plots of the four solar wind parameters over solar distance. The mean and median per 0.01 au data bin and their fit curves are plotted as well. The Helios data has a native distance resolution of 0.01 au ,thus, to make the distribution visible in these plots, we added a random distance value of up to ±0.005au. The high velocity data points above 800 km s⁻¹ (circled red) are identified as CME events (e.g., Sheeley et al. 1985; Bothmer & Schwenn 1996, 1998).