The outcome of the spot speed studies carried out at a certain stretch of a highway are as follows.

50th percentile speed = 46 km/h ; 75th percentile speed = 54 km/h ; 85th percentile speed = 60 km/h ; 95th percentile speed = 75 km/h ; 98th percentile speed = 84 km/h ; 100th percentile speed = 95 km/h

What is the speed (in km/h units) to be taken to check the geometric design elements.