According to the ITTF rules, how high must you throw the ball in the air to start a service?

Question

(in order for the service to be considered legal)

Answer 1

At least 16cm (approx 6 inches)
"The server shall then project the ball near vertically upwards, without imparting spin, so that it rises at least 16cm (approx 6 inches) after leaving the palm of the free hand and then falls without touching anything before being struck".