China is leading the way here. Although, I would personally estimate from observation that in Shenzhen the amount of monowheels visible on the streets perhaps p

China is leading the way here. Although, I would personally estimate from observation that in Shenzhen the amount of monowheels visible on the streets perhaps peaked last year and is now dropping. They have been largely supplanted by the stand-on two-footpad type (very popular with kids) and the scooter (adults).