Year Number 1950 61.72 1951 61.261 1952 60.748 1953 60.653 1954 61.16 1955 62.287 1956 64.732 1957 67.502 1958 70.647 1959 74.224 1960 78.25 1961 82.756 1962 87.596 1963 92.446 1964 96.739 1965 100.08 1966 103.462 1967 105.378 1968 106.163 1969 106.428 1970 106.535 1971 105.097 1972 104.133 1973 103.403 1974 102.351 1975 100.68 1976 99.404 1977 97.351 1978 94.862 1979 92.514 1980 90.638 1981 89.204 1982 88.351 1983 87.947 1984 87.745 1985 87.627 1986 88.197 1987 88.75 1988 89.314 1989 89.88 1990 90.353 1991 91.751 1992 92.629 1993 93.06 1994 93.147 1995 92.916 1996 92.212 1997 91.441 1998 90.396 1999 88.825 2000 86.691 2001 84.203 2002 81.288 2003 78.195 2004 75.274 2005 72.697 2006 70.178 2007 68.102 2008 66.379 2009 64.872 2010 63.538 2011 62.902 2012 62.309 2013 61.738 2014 61.242 2015 60.885 2016 61.431 2017 61.875 2018 62.316 2019 62.816 2020 63.349 2021 63.576 2022 63.917 2023 64.216 2024 64.28 2025 64.039 2026 63.663 2027 63.031 2028 62.196 2029 61.272 2030 60.336 2031 59.414 2032 58.5 2033 57.624 2034 56.806 2035 56.069 2036 55.503 2037 55.019 2038 54.619 2039 54.299 2040 54.052 2041 53.957 2042 53.903 2043 53.902 2044 53.954 2045 54.049 2046 54.219 2047 54.382 2048 54.561 2049 54.79 2050 55.079 2051 55.413 2052 55.794 2053 56.158 2054 56.422 2055 56.542 2056 56.549 2057 56.436 2058 56.233 2059 55.988 2060 55.738 2061 55.517 2062 55.291 2063 55.056 2064 54.799 2065 54.518 2066 54.252 2067 53.971 2068 53.703 2069 53.474 2070 53.303 2071 53.21 2072 53.149 2073 53.147 2074 53.241 2075 53.449 2076 53.768 2077 54.177 2078 54.646 2079 55.124 2080 55.571 2081 55.995 2082 56.399 2083 56.768 2084 57.093 2085 57.375 2086 57.619 2087 57.82 2088 57.987 2089 58.127 2090 58.243 2091 58.318 2092 58.377 2093 58.432 2094 58.496 2095 58.585 2096 58.669 2097 58.773 2098 58.912 2099 59.101 2100 59.35