Year Number 1950 42.799 1951 44.422 1952 46.025 1953 48.714 1954 52.58 1955 57.129 1956 60.995 1957 66.097 1958 71.444 1959 76.118 1960 79.923 1961 83.73 1962 85.813 1963 87.235 1964 88.683 1965 89.824 1966 91.469 1967 91.351 1968 89.435 1969 86.082 1970 81.795 1971 76.177 1972 71.298 1973 66.999 1974 63.01 1975 59.166 1976 57.07 1977 54.67 1978 52.345 1979 50.694 1980 50.084 1981 49.002 1982 48.591 1983 48.607 1984 48.529 1985 48.071 1986 48.628 1987 48.558 1988 48.122 1989 47.63 1990 47.2 1991 48.124 1992 48.691 1993 49.052 1994 49.219 1995 49.117 1996 48.476 1997 47.657 1998 46.549 1999 45.065 2000 43.267 2001 40.499 2002 37.997 2003 35.853 2004 34.086 2005 32.635 2006 30.874 2007 29.064 2008 27.36 2009 25.923 2010 24.881 2011 25.034 2012 25.456 2013 26.17 2014 27.108 2015 28.209 2016 29.764 2017 31.34 2018 32.998 2019 34.816 2020 36.811 2021 38.727 2022 40.847 2023 43.047 2024 45.153 2025 47.079 2026 48.908 2027 50.527 2028 51.942 2029 53.194 2030 54.315 2031 55.21 2032 55.928 2033 56.525 2034 57.075 2035 57.637 2036 58.092 2037 58.583 2038 59.084 2039 59.541 2040 59.936 2041 60.192 2042 60.378 2043 60.614 2044 61.069 2045 61.845 2046 62.825 2047 64.091 2048 65.602 2049 67.262 2050 68.995 2051 70.72 2052 72.524 2053 74.341 2054 76.067 2055 77.619 2056 78.894 2057 79.979 2058 80.855 2059 81.526 2060 82.017 2061 82.187 2062 82.181 2063 82.018 2064 81.7 2065 81.227 2066 80.426 2067 79.542 2068 78.597 2069 77.655 2070 76.791 2071 75.812 2072 74.903 2073 74.151 2074 73.625 2075 73.322 2076 72.985 2077 72.92 2078 73.056 2079 73.283 2080 73.557 2081 73.743 2082 74.023 2083 74.374 2084 74.786 2085 75.266 2086 75.64 2087 76.063 2088 76.539 2089 77.066 2090 77.633 2091 78.01 2092 78.413 2093 78.828 2094 79.252 2095 79.689 2096 79.884 2097 80.073 2098 80.278 2099 80.529 2100 80.832