Year Number 1950 80.307 1951 79.853 1952 80.173 1953 80.707 1954 81.153 1955 81.397 1956 81.711 1957 81.69 1958 81.653 1959 81.944 1960 82.683 1961 83.593 1962 84.796 1963 86.162 1964 87.393 1965 88.259 1966 88.536 1967 88.441 1968 88.092 1969 87.783 1970 87.821 1971 90.292 1972 93.289 1973 96.6 1974 99.803 1975 102.543 1976 103.085 1977 102.981 1978 102.573 1979 102.258 1980 102.204 1981 102.462 1982 102.796 1983 102.998 1984 102.74 1985 101.89 1986 100.739 1987 99.236 1988 97.398 1989 95.331 1990 93.168 1991 91.685 1992 89.974 1993 88.212 1994 86.581 1995 85.149 1996 84.241 1997 83.401 1998 82.605 1999 81.805 2000 80.973 2001 80.649 2002 80.371 2003 80.121 2004 79.85 2005 79.507 2006 79.336 2007 79.179 2008 79.037 2009 78.876 2010 78.629 2011 78.302 2012 77.712 2013 76.934 2014 76.044 2015 75.083 2016 74.079 2017 73.03 2018 71.932 2019 70.776 2020 69.574 2021 68.409 2022 67.264 2023 66.134 2024 65.032 2025 63.973 2026 63.117 2027 62.284 2028 61.495 2029 60.777 2030 60.139 2031 59.65 2032 59.217 2033 58.848 2034 58.551 2035 58.321 2036 58.213 2037 58.146 2038 58.098 2039 58.046 2040 57.976 2041 57.929 2042 57.852 2043 57.736 2044 57.569 2045 57.346 2046 57.102 2047 56.809 2048 56.468 2049 56.086 2050 55.668 2051 55.256 2052 54.812 2053 54.358 2054 53.925 2055 53.532 2056 53.218 2057 52.934 2058 52.685 2059 52.479 2060 52.321 2061 52.256 2062 52.228 2063 52.234 2064 52.267 2065 52.324 2066 52.447 2067 52.577 2068 52.724 2069 52.898 2070 53.102 2071 53.353 2072 53.622 2073 53.9 2074 54.172 2075 54.432 2076 54.685 2077 54.92 2078 55.133 2079 55.323 2080 55.492 2081 55.63 2082 55.74 2083 55.833 2084 55.924 2085 56.021 2086 56.114 2087 56.211 2088 56.317 2089 56.439 2090 56.581 2091 56.737 2092 56.911 2093 57.106 2094 57.328 2095 57.577 2096 57.833 2097 58.114 2098 58.42 2099 58.748 2100 59.096