Year Million Current Pounds 1911 11.2000 1912 10.8000 1913 12.1800 1914 11.1800 1915 7.29000 1916 5.26000 1917 4.93000 1918 5.23000 1919 25.0700 1920 45.1500 1921 18.5900 1923 28.8500 1924 33.8000 1925 37.7300 1926 41.3200 1927 39.6100 1928 39.5500 1929 42.7100 1930 41.9600