Year Millions Of Passengers 1919 15.3130 1920 15.9980 1921 15.1980 1922 16.1610 1923 16.7060 1924 16.6380 1925 16.7410 1926 17.0840 1927 16.8850 1928 16.5030 1929 16.3710 1930 15.0700 1931 13.6580 1932 11.6970 1933 11.0510