Table:
text: General Motors
Brand reorganization
Brand reorganization
Brand Year_founded Year_began_making_autos Year_joined_GM Markets_served_today
Baojun 2010 2010 2010 China
Buick 1899 1903 1908 North America, China, Israel
Cadillac 1902 1902 1909 North America, Europe, Asia, Middle East
Chevrolet 1911 1911 1917 Global, except Australia, New Zealand
GMC 1901 1901 1909 North America, Middle East
Holden 1856 1908 1931 Australia, New Zealand
Jiefang 2011 2011 2011 China
Opel 1862 1899 1929 Africa, Asia, Europe, South America
Wuling 2002 2002 2002 China
Vauxhall 1857 1903 1925 United Kingdom

Question: What is the average year to start making cars for a brand that joined GM in 1917 for General Motors?