Notable malls include:  Bogota is home to like Canal Capital and Citytv which are local stations, Canal 13 is a regional station, and is home to the national channels Caracol TV, RCN TV, Canal Uno, Canal Institucional, and Señal Colombia. It has multiple satellite television services like Telefónica, Claro and DirecTV and several satellite dishes which offer hundreds of international channels, plus several exclusive channels for Bogotá. In Bogota, all the major radio networks in the country are available, in both AM and FM; 70% of the FM stations offer RDS service. There are several newspapers, including "El Tiempo", "El Espectador" and "El Nuevo Siglo", plus economical dailies "La República" and "Portafolio", tabloids "El Espacio", "Q'Hubo", and "Extra". Bogotá also offers three free newspapers, two Spanish, ADN and Publimetro, and one English, The Bogota Post. Energy and sewer bills are stratified based on the location of owner's residence, The system is the classification of the residential properties that should receive public services. Although the system does not consider the income per person and the rules say that the residential real estate should stratify and not households. All mayors should do the stratification of residential properties of their municipality or district. Bogotá's social strata have been divided as follows and have been extensively used by the government as a reference to develop social welfare programs, statistical information and to some degree for the assignment of lands. Bogotá's growth has placed a strain on its roads and highways, but since 1998 significant efforts to upgrade the infrastructure have been undertaken. Private car ownership forms a major part of the congestion, in addition to taxis, buses and commercial vehicles. Buses remain the main means of mass transit. There are two bus systems: the traditional system and the TransMilenio. The traditional system runs a variety of bus types, operated by several companies on normal streets and avenues: "Bus" (large buses), "Buseta" (medium size buses) and "Colectivo" (vans or minivans). The bigger buses were divided into two categories: "Ejecutivo", which was originally to be a deluxe service and was not to carry standing passengers, and "corriente" or normal service. Since May 2008, all buses run as "corriente" services.