(Yicai Global) June 21 -- Wang Lixin, vice mayor of Shenzhen, said today that Shenzhen has become the most important production base for drones worldwide after several years of hard work. By the end of 2018, there were more than 360 drone company in the city with a combined annual turnover in excess of CNY40 billion (USD5.8 billion), the Shenzhen Special Zone Daily reported.