Whats a minimal age to ride a segway?

Since 2018 there were approved a new segway regulations in Madrid and now rides for kids under 12 is not allowed.
For underage we provide mini e-bikes Xiaomi, or kick-scooter Xiaomi Pro, so kids can take part in the tour on it.
The minimum age for riding those is 8 years.
By the way minimal weight to ride a segway is 35 kg.