Year Number 1950 75.493 1951 76.106 1952 76.643 1953 76.807 1954 76.528 1955 75.885 1956 76.806 1957 77.141 1958 77.145 1959 77.102 1960 77.158 1961 78.435 1962 79.677 1963 80.852 1964 81.851 1965 82.616 1966 84.303 1967 85.634 1968 86.671 1969 87.5 1970 88.167 1971 89.62 1972 90.77 1973 91.653 1974 92.301 1975 92.742 1976 93.793 1977 94.543 1978 95.041 1979 95.335 1980 95.46 1981 96.192 1982 96.633 1983 96.848 1984 96.903 1985 96.832 1986 97.318 1987 97.568 1988 97.627 1989 97.54 1990 97.339 1991 96.984 1992 96.435 1993 95.754 1994 94.966 1995 94.079 1996 94.351 1997 94.382 1998 94.222 1999 93.936 2000 93.567 2001 93.054 2002 92.405 2003 91.65 2004 90.794 2005 89.846 2006 89.429 2007 88.825 2008 88.07 2009 87.197 2010 86.223 2011 85.61 2012 84.853 2013 83.979 2014 83.013 2015 81.982 2016 81.156 2017 80.254 2018 79.288 2019 78.272 2020 77.219 2021 76.435 2022 75.563 2023 74.643 2024 73.716 2025 72.805 2026 72.12 2027 71.41 2028 70.679 2029 69.923 2030 69.143 2031 68.55 2032 67.903 2033 67.216 2034 66.502 2035 65.773 2036 65.208 2037 64.596 2038 63.951 2039 63.285 2040 62.607 2041 62.078 2042 61.511 2043 60.919 2044 60.315 2045 59.707 2046 59.243 2047 58.753 2048 58.246 2049 57.73 2050 57.215 2051 56.841 2052 56.441 2053 56.028 2054 55.613 2055 55.206 2056 54.933 2057 54.644 2058 54.344 2059 54.04 2060 53.736 2061 53.556 2062 53.352 2063 53.134 2064 52.913 2065 52.695 2066 52.595 2067 52.473 2068 52.336 2069 52.188 2070 52.036 2071 51.984 2072 51.906 2073 51.807 2074 51.693 2075 51.568 2076 51.537 2077 51.474 2078 51.389 2079 51.294 2080 51.198 2081 51.199 2082 51.178 2083 51.141 2084 51.092 2085 51.036 2086 51.079 2087 51.094 2088 51.088 2089 51.072 2090 51.054 2091 51.131 2092 51.187 2093 51.226 2094 51.253 2095 51.271 2096 51.399 2097 51.498 2098 51.574 2099 51.637 2100 51.695