Year Millions Of Passengers 1911 22.5020 1912 23.5570 1913 26.1320 1914 25.0460 1915 25.5460 1916 27.8660 1917 32.2610 1918 28.7510 1919 37.3460 1920 39.2550 1921 31.2250 1922 31.7480 1923 34.2490 1924 34.0860 1925 35.5260 1926 36.0730 1927 35.1970 1928 33.9240 1929 33.4340 1930 29.3600 1931 22.9850 1932 15.7500 1933 13.7170 1934 15.1050 1935 15.4790 1936 17.1980 1937 17.7450