The oldest, which dates back to 1998, is called the Hamburg Index.[50] This index considers time-charters on fully cellular containerships controlled by Hamburg brokers.[50] It is limited to charters of 3 months or more, and presented as the average daily cost in U.S. dollars for a one-TEU slot with a weight of 14 tonnes.[50] The Hamburg Index data is divided into ten categories based primarily on vessel carrying capacity.[50] Two additional categories exist for small vessels of under 500 TEU that carry their own cargo cranes.[50] In 2007, VHSS started another index, the New ConTex which tracks similar data obtained from an international group of shipbrokers.[50]