Assuming a wind log law profile determine the height of the chosen wind speed data. This can be estimated by calculating the average wind speed from the data and using as reference the average wind speed provided in the wind atlas https://globalwindatlas.info/en/area/Australia at 100 m at the location corresponding to your data. Determine at the location the roughness length, zo, also provided by the wind atlas. Convert your column of wind speeds from the above determined height to 100 m (hub height), using the log law to determine the wind speed gradient