Year Total 1925 4.382 1926 4.39 1927 4.398 1928 4.406 1929 4.414 1930 4.422 1931 4.363 1932 4.304 1933 4.245 1934 4.186 1935 4.127 1936 3.932 1937 3.736 1938 3.54 1939 3.345 1940 3.149 1941 3.321 1942 3.492 1943 3.664 1944 3.835 1945 4.007 1946 4.11 1947 4.213 1948 4.316 1949 4.42 1950 4.523 1951 4.453 1952 4.322 1953 4.207 1954 4.109 1955 4.028 1956 3.964 1957 3.915 1958 3.88 1959 3.857 1960 3.843 1961 3.835 1962 3.83 1963 3.824 1964 3.817 1965 3.81 1966 3.804 1967 3.803 1968 3.806 1969 3.812 1970 3.817 1971 3.813 1972 3.798 1973 3.767 1974 3.722 1975 3.662 1976 3.59 1977 3.511 1978 3.43 1979 3.351 1980 3.28 1981 3.219 1982 3.17 1983 3.133 1984 3.106 1985 3.087 1986 3.072 1987 3.057 1988 3.04 1989 3.019 1990 2.996 1991 2.973 1992 2.952 1993 2.937 1994 2.928 1995 2.924 1996 2.924 1997 2.925 1998 2.925 1999 2.924 2000 2.921 2001 2.918 2002 2.914 2003 2.912 2004 2.91 2005 2.91 2006 2.911 2007 2.913 2008 2.916 2009 2.919 2010 2.92 2011 2.917 2012 2.91 2013 2.898 2014 2.882 2015 2.861 2016 2.838 2017 2.813 2018 2.788 2019 2.763 2020 2.74 2021 2.718 2022 2.698 2023 2.677 2024 2.657 2030 2.54 2040 2.37 2050 2.221 2070 2.023 2080 1.97 2099 1.917