Please answer a question about the following article about Switzerland:

Skiing, snowboarding and mountaineering are among the most popular sports in Switzerland, the nature of the country being particularly suited for such activities. Winter sports are practiced by the natives and tourists since the second half of the 19th century with the invention of bobsleigh in St. Moritz. The first world ski championships were held in Mürren (1931) and St. Moritz (1934). The latter town hosted the second Winter Olympic Games in 1928 and the fifth edition in 1948. Among the most successful skiers and world champions are Pirmin Zurbriggen and Didier Cuche.

When were the first ski championships held in Murren?
1931