More than 60% of licences are assigned (or leased or rented) to taxi operators, who pay the licence holder assignment fees. These fees fluctuate, and typically are in the order of $24,000 per annum. The operator owns, maintains and operates the taxi vehicle as well as the taximeter. Taxi operators may drive their taxis or may employ drivers. In June 2016 there were 14,771 active taxi drivers. Taxi drivers are required to be registered, and their registration certificate must be displayed in the taxi. A taxi operator can sell the taxi, comprising the assigned licence, vehicle and meter, as a going concern. Besides receiving the assignment fees from the taxi operator, licence holders also commonly benefit from capital growth in licence values, or carry the risk of a decline in the market value of a licence.