Recuperation values are difficult to assess.
The most efficient driving is a recuperation value of 0 kWh/100 km which means that all decelerations are accomplished by coasting only (i.e., no regenerative or friction braking). This is impossible to accomplish in real-world driving.
If one decelerated only by pressing the friction brake pedal very aggressively, regenerative braking would occur over a short period of time resulting in a low but greater than 0 kWh/100 km recuperation value which is the least efficient way to drive (much of the vehicle's momentum would be converted to waste heat by the friction brakes).
If one decelerated using only regenerative braking, a higher recuperation value would result. Stop-and-go traffic should result in a higher kWh/100 km value due to an increased frequency of regenerative braking. Driving efficiency would be worse than coasting but better than aggressively friction braking. This describes how I drive most of the time in our suburban/urban setting with frequent traffic lights and generally moderate traffic. The BMW Connected app claims that 21 mi/kWh (3.0 kWh/100 km) is my lifetime recuperation value over 5.5 years of driving our 2014 BEV.
2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE