Division in the Battle of the Somme. End of World War I. Influenza pandemic in which an estimated 8,500 die. Creation of power boards for electricity distribution. Prohibition petition with 242,001 signatures presented to Parliament. 1919 Women eligible for election to Parliament. Massey signs Treaty of Versailles. First official airmail flight from Auckland to Dargaville. 17 December: 1919 New Zealand general election. 1920s 1920 Anzac Day established. New Zealand gets League of Nations mandate to govern Western Samoa. First aeroplane flight across Cook Strait. New Zealand sends first team to Olympic Games (previously they have competed as part of Australasian team). Darcy Hadfield wins first Olympic medal for New Zealand. 1921 New Zealand Division of the Royal Navy established. 1922 New Zealand Meat Producers Board constituted under Act of Parliament and placed in control of meat exports. 7 December: 1922 New Zealand general election. 1923 New Zealand Dairy Board constituted under Act of Parliament and placed in control of Dairy exports Otira tunnel opens; Midland Line between Christchurch and Greymouth completed Ross Dependency proclaimed. 1924 All Black 'Invincibles' tour of Britain and France. 1925 4 November: General election won by the Reform party under Gordon Coates. 1926 National public broadcasting begins under auspices of Radio Broadcasting Co. Ltd. 1927 1928 New Zealand Summer Time introduced. Charles Kingsford Smith completes first flight across Tasman Sea. 14 December: General election won by new United Party. Ted Morgan wins first Olympic gold medal for New Zealand. 1929 Economic depression worsens. Severe earthquake in the Murchison – Karamea district results in 17 deaths. First health stamps issued. 1930s 1930 Unemployment Board set up to provide relief work. 1931 3 February: A magnitude 7.8 earthquake in Hawke's Bay kills 256 people. Substantial percentage reductions in public service wages and salaries, to help rebuild Hawke's Bay. Airmail postage stamps introduced. 2 December: General election won by newly formed Coalition Government under George Forbes. 1932 Compulsory arbitration of industrial disputes abolished. Unemployed riots in Auckland, Dunedin and Christchurch. Reductions in old-age and other pensions. Distinctive New Zealand coins first issued, see New Zealand pound. 1933 9 September: Elizabeth McCombs becomes first woman MP. 1934 Reserve Bank and Mortgage Corporation established. First trans-Tasman airmail. 1935 Air services begin across Cook Strait. 24 November: New Zealand Post Office jams 1ZB radio broadcast by Colin Scrimgeour (Uncle Scrim). 27 November: General election: First Labour Government elected under Michael Joseph Savage.