AirborneWindEnergy: For More Power From On High (Luke1:3KJV)

4879 m in 2014.

4422 m in 2000.

And as you indicate @AweEnthusiast, 9740 m in 1919, so more than twice the altitude reached by a single kite.

Indeed kite altitude is important for AWE, which intends to harness high altitude wind energy.