At the same time, despite the Occupation, commercial activities began to flourish and demand for telecommunications services increased greatly. This necessitated a third floor to be built at the telephone exchange building in Kuala Lumpur. Along with the issue of 10 cent coins, phone booths began to spring up in Kuala Lumpur and Penang. From 1950 to 1953, the Department's revenue more than doubled from $8 million to $17 million as the number of telephones installed rose from 20,000 to 39,000. Accordingly, the trunk and junction networks expanded, and the number of radio stations grew by 10 times to more than 1,000. In 1953, too, the Penang Auto Exchange was opened catering for 5,000 lines. In 1954, the Main Trunk Route linking Singapore to Malacca, Kuala Lumpur and Penang was completed. Satellite exchanges began to emerge. During this period, international connections have also increased, linking Malaysia with the rest of the world.