Year Number 1950 48.67 1951 49.397 1952 50.39 1953 51.076 1954 51.346 1955 51.322 1956 52.068 1957 52.229 1958 52.161 1959 52.145 1960 52.247 1961 51.887 1962 51.728 1963 51.621 1964 51.362 1965 50.893 1966 50.294 1967 49.726 1968 49.157 1969 48.585 1970 48.041 1971 48.186 1972 48.067 1973 47.946 1974 48.185 1975 48.941 1976 49.927 1977 51.557 1978 53.425 1979 54.8 1980 55.244 1981 55.485 1982 54.557 1983 53.004 1984 51.685 1985 51.027 1986 50.443 1987 50.724 1988 51.38 1989 51.678 1990 51.287 1991 51.303 1992 50.596 1993 49.502 1994 48.521 1995 47.869 1996 47.576 1997 47.435 1998 47.38 1999 47.253 2000 46.984 2001 46.625 2002 46.302 2003 45.988 2004 45.675 2005 45.376 2006 45.429 2007 45.459 2008 45.492 2009 45.565 2010 45.698 2011 46.043 2012 46.359 2013 46.725 2014 47.223 2015 47.878 2016 48.698 2017 49.721 2018 50.818 2019 51.808 2020 52.597 2021 53.451 2022 54.089 2023 54.532 2024 54.824 2025 54.984 2026 55.073 2027 55.035 2028 54.927 2029 54.826 2030 54.788 2031 54.931 2032 55.146 2033 55.428 2034 55.761 2035 56.135 2036 56.654 2037 57.214 2038 57.855 2039 58.648 2040 59.64 2041 60.963 2042 62.488 2043 64.106 2044 65.613 2045 66.859 2046 67.952 2047 68.781 2048 69.421 2049 70.004 2050 70.618 2051 71.314 2052 72.029 2053 72.738 2054 73.41 2055 74.036 2056 74.641 2057 75.207 2058 75.702 2059 76.065 2060 76.246 2061 76.227 2062 76.042 2063 75.731 2064 75.369 2065 75.013 2066 74.696 2067 74.39 2068 74.13 2069 73.926 2070 73.759 2071 73.681 2072 73.722 2073 73.809 2074 73.868 2075 73.886 2076 73.943 2077 73.969 2078 74.009 2079 74.108 2080 74.268 2081 74.428 2082 74.662 2083 74.947 2084 75.244 2085 75.528 2086 75.756 2087 76.013 2088 76.276 2089 76.527 2090 76.769 2091 76.921 2092 77.07 2093 77.223 2094 77.387 2095 77.556 2096 77.574 2097 77.618 2098 77.688 2099 77.774 2100 77.866