Year Number 1950 82.414 1951 82.492 1952 82.1 1953 81.725 1954 81.626 1955 81.739 1956 81.056 1957 80.74 1958 80.551 1959 80.18 1960 79.561 1961 83.067 1962 85.995 1963 88.981 1964 92.151 1965 94.88 1966 93.387 1967 92.177 1968 91.353 1969 90.751 1970 90.207 1971 87.029 1972 82.947 1973 78.733 1974 75.094 1975 72.281 1976 68.174 1977 64.867 1978 62.215 1979 59.926 1980 57.811 1981 57.109 1982 56.765 1983 56.667 1984 56.686 1985 56.707 1986 56.469 1987 55.871 1988 55.185 1989 54.46 1990 53.553 1991 53.129 1992 52.249 1993 51.058 1994 49.727 1995 48.489 1996 48.358 1997 48.078 1998 48.139 1999 48.699 2000 49.579 2001 46.952 2002 44.835 2003 43.257 2004 42.035 2005 40.971 2006 37.032 2007 33.847 2008 31.315 2009 29.328 2010 27.796 2011 28.594 2012 29.353 2013 30.136 2014 30.863 2015 31.382 2016 31.278 2017 30.962 2018 30.564 2019 30.245 2020 30.068 2021 29.813 2022 29.768 2023 29.849 2024 29.893 2025 29.814 2026 29.857 2027 29.701 2028 29.502 2029 29.427 2030 29.53 2031 29.67 2032 29.911 2033 30.294 2034 30.795 2035 31.382 2036 32.01 2037 32.694 2038 33.435 2039 34.206 2040 34.972 2041 35.674 2042 36.322 2043 36.993 2044 37.771 2045 38.693 2046 39.656 2047 40.713 2048 41.863 2049 43.044 2050 44.202 2051 45.252 2052 46.223 2053 47.196 2054 48.22 2055 49.308 2056 50.357 2057 51.417 2058 52.512 2059 53.636 2060 54.769 2061 55.796 2062 56.801 2063 57.791 2064 58.719 2065 59.535 2066 60.115 2067 60.55 2068 60.935 2069 61.392 2070 61.992 2071 62.596 2072 63.287 2073 64.1 2074 65.008 2075 65.959 2076 66.804 2077 67.699 2078 68.6 2079 69.419 2080 70.092 2081 70.489 2082 70.711 2083 70.847 2084 70.99 2085 71.171 2086 71.212 2087 71.282 2088 71.401 2089 71.552 2090 71.703 2091 71.709 2092 71.743 2093 71.819 2094 71.939 2095 72.099 2096 72.142 2097 72.198 2098 72.3 2099 72.478 2100 72.728