(and in Bærum), the metro is often called trikken ("the tramway"), because as a local railway connection, it received the same colloquial name as the city tram line (bytrikken), because the trams were in use for many years before they were coupled together with the eastern metro lines. When trikken is used as a name for the metro, "blåtrikken" is often also used for the city's tram lines, because the tram cars have been blue in colour for many years. There are significant differences in what first names are popular in the East End and in the West End. Name fashions change, geographically and socially, from the city centre to the outskirts and from the upper class to the worker class. The main image is that the West End and Bærum set the trends for first names in Norway, the East End and the rest of the country follow behind. The newest data on the name situation at district level detail is from 1997. At that time, typical West End names were Henrik, Carl, Haakon, Bendik, Jens, Peder, William, Magnus, Axel, Nora, Thea, Andrea, Anna, Cecilie, Hanna, Hedda, Julie, Oda, Vibeke and Vilde. Many of them were very common names in the last turn of the 20th century, and with Norwegian and Nordic origins, including many names of royalty. The tradition that royalty names are more common in the West End is related to the fact that the West End, with its bourgeois, was closely related to Denmark for a long time, and therefore people gave their children conservative, Danish names. This tradition still survives to this day, although at a lesser level than before. Typical East End names were Daniel, Glenn, Tommy, Christer, Frank, Johnny, Anita, Jeannette, Mona, Nadia and Monica. Names such as Linda, Jeannette, Kim, Patrick and Robin were first taken into use in the West End, but are today most used in the East End. Many East End names trace their origins from English names. A group of names has been neutral in regard to the east-west division: Bente, Elin, Grete, Gunn, Merete, Siv, Espen, Geir, Kristian, Markus, Simon, Sindre, Thomas, Johan, Jens. Immigration has changed the situation. In 2008, 120 boys from Oslo were named Mohammad, and this was the most common name among boys born in Oslo in that year. For the 21st century, there is not yet data about use of names divided